Onan starting

[a.]

> Thanks again for all the help, here's what I know.
> I have oil pressure and the oil pressure switch works fine as does a new one I bought.
>
> Jumping pins 5 & 9 on the control board bypasses several error conditions, not just low oil pressure which is why I now have a spare oil pressure
> switch.
>
> The generator doesn't stay running because I don't not have 28 volts on pin 11 which points to a possible voltage regulator issue but not
> exclusively. Duane's troubleshooting tips seems to be incomplete as it describes removing and insulating the connectors to it but then it stops
> there with no further info on a next step if there is one. Is there a further test of the regulator?
Duane's instructions for removing and isolating the wires takes the voltage regulator out of the picture. If you do not have near 28 volts on pin 11
when you have removed and insulated the wires from the voltage regulator, you have something else keeping pin 11 from getting 28 volts. It could be a
bad wire between the regulator and pin 11, or a bad connection in that "splice" where the wire came from the flywheel to the regulator and then onward
to pin 11. Or it could be a bad flywheel alternator.

My money is on a bad connection between the flywheel alternator and pin 11. Clean the contacts in that "splice" that used to be where the wire from
the flywheel went to the regulator and from there to pin 11.

If that doesn't get you 28VAC at pin 11, and you have a bad flywheel alternator, you can either do some major surgery to repair it (involves removing
and taking apart the Onan) or you can figure out another way to get 28VAC to pin 11.

Make sure your meter is set for AC when checking that voltage. It is not DC.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[ken harland]

> Ken,
> Here is the link to the info on the Charger/Alternator Regulator Removal. As John L said it serves not useful purpose and can cause problems with
> the newer style charger/converters went they are run with the generator.

I didn't get that he said they're weren't useful, does that mean simply remove it?

Quote:
> Go Here:
>
> http://bdub.net/gmcmotorhome.info/generator.html

Thanks, that's a better source for Onan info. I'll spend some time there after trying Matt's suggestion.

Quote:
> Gene's link to the newer propane conversion is not the only good choice to help your onan. The upgrade to the newer electronic ignition is also a
> very good upgrade to smooth out a rough running generator. It would be my first choice before the expense of the propane conversion and would help
> the generator run extremely well with propane as the main fuel.

Frankly I would never convert an Onan to propane. Our previous coach was a diesel with a converted Onan and I disliked it so much I was about to
install a separate gasoline tank and convert it back before we sold it. It was a major traveling inconvenience to have to search for a propane fill
station when we stopped to refuel. At least with it on gasoline we could fill both tanks at one location whenever we stopped.

Plus propane has considerbly less energy content and therefore will consume more fuel than it does with gasoline. That will require more frequent
searching for propane filling stations as you travel and that's an unnecessary inconvenience. As it is our consumption of propane is very low and
refilling is an infrequent exercise and our genset runs fine on gasoline.

Quote:
> Electronic Ignition Conversion:
>
> http://bdub.net/gmcmotorhome.info/generator.html
> and
> http://www.gmcmhphotos.com/photos/g3608-onan-ignition-upgrade-to-pertronix.html
> and
> http://www.picturetrail.com/sfx/album/view/1344546
>
> Over the years we have had many upgrade to the systems of our coaches and these are 2 of the many good things designed.

That is something I anticipate is in my future, just isn't needed right now.

Quote:
> J.R. Wright
> GMC GreatLaker
> Newsletter Editor/Publisher
> Tech Editor
> 78 Buskirk 30' Stretch
> 75 Avion Under Reconstruction
> Michigan

--
1978 Eleganza II

 

[Jim Hupy]

The output from the stator on the flywheel of the Onan is A.C. and varies
with engine rpm. The finned rectifier/regulator does two things. It changes
the A.C. output to D.C. and limits output to something near 28 volts for
the relay on the Onan Control board that senses whether or not the engine
is running. Dwayne spells out a method for discontinuation of the regulator
in his article. If your Onan is started from the coach batteries, you don't
need the flywheel alternator. Your batteries are charged by the converter
or main engine alternator.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Thanks again for all the help, here's what I know.
> I have oil pressure and the oil pressure switch works fine as does a new
one I bought.
>
> Jumping pins 5 & 9 on the control board bypasses several error
conditions, not just low oil pressure which is why I now have a spare oil
pressure
> switch.
>
> The generator doesn't stay running because I don't not have 28 volts on
pin 11 which points to a possible voltage regulator issue but not
> exclusively. Duane's troubleshooting tips seems to be incomplete as it
describes removing and insulating the connectors to it but then it stops
> there with no further info on a next step if there is one. Is there a
further test of the regulator?
Duane's instructions for removing and isolating the wires takes the voltage
regulator out of the picture. If you do not have near 28 volts on pin 11
when you have removed and insulated the wires from the voltage regulator,
you have something else keeping pin 11 from getting 28 volts. It could be a
bad wire between the regulator and pin 11, or a bad connection in that
"splice" where the wire came from the flywheel to the regulator and then
onward
to pin 11. Or it could be a bad flywheel alternator.

My money is on a bad connection between the flywheel alternator and pin 11.
Clean the contacts in that "splice" that used to be where the wire from
the flywheel went to the regulator and from there to pin 11.

If that doesn't get you 28VAC at pin 11, and you have a bad flywheel
alternator, you can either do some major surgery to repair it (involves
removing
and taking apart the Onan) or you can figure out another way to get 28VAC
to pin 11.

Make sure your meter is set for AC when checking that voltage. It is not DC.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[a.]

> > Ken,
> > Here is the link to the info on the Charger/Alternator Regulator Removal. As John L said it serves not useful purpose and can cause problems
> > with the newer style charger/converters went they are run with the generator.
>
> I didn't get that he said they're weren't useful, does that mean simply remove it?
Here's the history you might not know.

The first GMCs had a dedicated start battery for the Onan. Later models used the house battery to start the Onan. And the converter/charger of the
later models kept the house battery charged, so the Onan battery charging system was not only not necessary, it could (in theory) interfere with the
converter/charger keeping the house battery charged. Removing the Onan's native charging is simple and can only be a good idea with no downside in
those GMCs.

If you have an older model with a dedicated Onan start battery, you can't bypass the voltage regulator without rigging something to recharge the
battery after a start and keep it charged while the Onan is running.

Yours is a '78, so it should be using the house battery to start and run the Onan. If a PO hasn't backgraded it to a dedicated Onan battery, you don't
need the voltage regulator. So you don't need to test it. Just take it out of the picture.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[ken harland]

> The output from the stator on the flywheel of the Onan is A.C. and varies
> with engine rpm. The finned rectifier/regulator does two things. It changes
> the A.C. output to D.C. and limits output to something near 28 volts for
> the relay on the Onan Control board that senses whether or not the engine
> is running. Dwayne spells out a method for discontinuation of the regulator
> in his article. If your Onan is started from the coach batteries, you don't
> need the flywheel alternator. Your batteries are charged by the converter
> or main engine alternator.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403

Thanks Jim, that's helpful to understand the function of that regulator but it leaves me with a couple of questions. You say it rectifies the AC to
DC but A's post says the 28 volts is AC. That wasn't clear to me from the Onan notes from Dwayne (Duane?) so my earlier test is possibly incorrect.
There is in fact 28 (well, 27.2) AC volts at pin 11 so I'd say the regulator isn't the problem if AC is what I'm looking for. I'll check the relay to
see if it's not pulling in when I get back to it tomorrow.

Quote:

>
> Duane's instructions for removing and isolating the wires takes the voltage
> regulator out of the picture. If you do not have near 28 volts on pin 11
> when you have removed and insulated the wires from the voltage regulator,
> you have something else keeping pin 11 from getting 28 volts. It could be a
> bad wire between the regulator and pin 11, or a bad connection in that
> "splice" where the wire came from the flywheel to the regulator and then
> onward
> to pin 11. Or it could be a bad flywheel alternator.
>
> My money is on a bad connection between the flywheel alternator and pin 11.
> Clean the contacts in that "splice" that used to be where the wire from
> the flywheel went to the regulator and from there to pin 11.
>
> If that doesn't get you 28VAC at pin 11, and you have a bad flywheel
> alternator, you can either do some major surgery to repair it (involves
> removing
> and taking apart the Onan) or you can figure out another way to get 28VAC
> to pin 11.
>
> Make sure your meter is set for AC when checking that voltage. It is not DC.

--
1978 Eleganza II

 

[a.]

> Thanks Jim, that's helpful to understand the function of that regulator but it leaves me with a couple of questions. You say it rectifies the AC
> to DC but A's post says the 28 volts is AC. That wasn't clear to me from the Onan notes from Dwayne (Duane?) so my earlier test is possibly
> incorrect. There is in fact 28 (well, 27.2) AC volts at pin 11 so I'd say the regulator isn't the problem if AC is what I'm looking for. I'll
> check the relay to see if it's not pulling in when I get back to it tomorrow.
For the voltage on pin 8, the voltage regulator is not actually in the circuit. The 28VAC comes off the flywheel alternator by a wire that goes to a
three-way connector on one "AC" pin on the voltage regulator. The other wire on that three-way connector goes to pin 8 on the control board. That
three-way connector is just a connection/splitter for getting the flywheel alternator voltage to both the voltage regulator and pin 8 of the control
board. The only other wire on the voltage regulator is the rectified and regulated 12VDC that goes from the "B+" pin of the voltage regulator to pin 5
on the control board where it charges the battery, provides the voltage to run the ignition system, powers the fuel pump, and opens the fuel
solenoid.

Check the schematic.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[Jim Hupy]

I don't think that is how it works. I am very knowledgeable on that Onan
flywheel alternator. Read manual to be sure if you doubt what I say.
Jim Hupy

> > Thanks Jim, that's helpful to understand the function of that regulator
> but it leaves me with a couple of questions. You say it rectifies the AC
> > to DC but A's post says the 28 volts is AC. That wasn't clear to me
> from the Onan notes from Dwayne (Duane?) so my earlier test is possibly
> > incorrect. There is in fact 28 (well, 27.2) AC volts at pin 11 so I'd
> say the regulator isn't the problem if AC is what I'm looking for. I'll
> > check the relay to see if it's not pulling in when I get back to it
> tomorrow.
> For the voltage on pin 8, the voltage regulator is not actually in the
> circuit. The 28VAC comes off the flywheel alternator by a wire that goes to
> a
> three-way connector on one "AC" pin on the voltage regulator. The other
> wire on that three-way connector goes to pin 8 on the control board. That
> three-way connector is just a connection/splitter for getting the flywheel
> alternator voltage to both the voltage regulator and pin 8 of the control
> board. The only other wire on the voltage regulator is the rectified and
> regulated 12VDC that goes from the "B+" pin of the voltage regulator to pin
> 5
> on the control board where it charges the battery, provides the voltage to
> run the ignition system, powers the fuel pump, and opens the fuel
> solenoid.
>
> Check the schematic.
> --
> 73 23' Sequoia 4 Sale
> 73 23' CanyonLands Parts Unit 4 Sale
> Upper Alabama
> "Highest price does not guarantee highest quality."
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[ken harland]

> I don't think that is how it works. I am very knowledgeable on that Onan
> flywheel alternator. Read manual to be sure if you doubt what I say.
> Jim Hupy

If this reply is for me, I didn't think I was questioning anything you described, just confused by your comment about the output of the regulator
being DC whereas elsewhere I was told it was AC. A Hamilton's response above clarifies the confusion, at least for me.

--
1978 Eleganza II

 

[Matt Colie]

> Thanks John,
>
> Can the regulator be tested in any way?
>
> I have done the other items you've suggested and found nothing amiss. I'm going to try Matt's suggestions next.
>
> Ken

Ken,

The regulator can be tested with a little bit of a haywire test stand. I used a door bell transformer to replace the alternator.
But seriously, if you don't need it, leave it out.
The Prestolite regulators are so primitive that they can't actually interfere with much, but why bother. I do need mine to charge the APU battery but
I am still working on how to get around that without spending a fortune for copper and then having to find the path for the corner to corner run.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[a.]

> I don't think that is how it works. I am very knowledgeable on that Onan flywheel alternator.
> Read manual to be sure if you doubt what I say.
> Jim Hupy
This is the schematic from the 6kW manual I have. I don't use it much because I use the 4kW one since I have a 4kW. But the flywheel alternator/3-way
connector/voltage regulator stuff is the same on this as the 4kW.

Maybe your manual has a different schematic?
http://www.gmcmhphotos.com/photos/data/10/Onan_Schematic.jpg
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[a.]

> Ken,
> The regulator can be tested with a little bit of a haywire test stand. I used a door bell transformer to replace the alternator.
> But seriously, if you don't need it, leave it out.
> The Prestolite regulators are so primitive that they can't actually interfere with much, but why bother. I do need mine to charge the APU battery
> but I am still working on how to get around that without spending a fortune for copper and then having to find the path for the corner to corner
> run.
>
> Matt
I need to test my regulator. Can you provide some more details for using a doorbell transformer. All I see locally are 24VAC transformers. Is that
supposedly close enough to 28VAC to do a test?
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[Matt Colie]

> Ken,
> The regulator can be tested with a little bit of a haywire test stand. I used a door bell transformer to replace the alternator.
>
> Matt

> I need to test my regulator. Can you provide some more details for using a doorbell transformer. All I see locally are 24VAC transformers. Is that
> supposedly close enough to 28VAC to do a test?

A,

The regulators are just a little upgrade from flint-lock.
They are just at simple rectifier and clipping circuit. They can behave badly without a battery for output load.
When I have tested them, a bell transformer was just fine. Actually, those are cheaper now than they used to be so the unloaded output is usually
high from the specified 24VAC.
They are designed for 2 phase AC, but the Onan only uses half. I have tested both ways because my Kohlers do use the 2 phase, but it makes little
difference.
Essentially, you feed it AC and it outputs about 15VDC that is seriously ragged. If you have it on a battery when you power the regulator up, you
should see the battery terminal go up, but maybe not a lot. I have never tested to see what the single phase output is, but on a Kohler, they can get
close to 15 amp for a short time.

I have only seen them go open. There has never been one of mine that went solid and either let AC through or more than ~15VDC.

Hope this is a help.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[a.]

> A,
> The regulators are just a little upgrade from flint-lock.
> They are just at simple rectifier and clipping circuit. They can behave badly without a battery for output load.
> When I have tested them, a bell transformer was just fine. Actually, those are cheaper now than they used to be so the unloaded output is usually
> high from the specified 24VAC.
> They are designed for 2 phase AC, but the Onan only uses half. I have tested both ways because my Kohlers do use the 2 phase, but it makes little
> difference.
> Essentially, you feed it AC and it outputs about 15VDC that is seriously ragged. If you have it on a battery when you power the regulator up, you
> should see the battery terminal go up, but maybe not a lot. I have never tested to see what the single phase output is, but on a Kohler, they can
> get close to 15 amp for a short time.
>
> I have only seen them go open. There has never been one of mine that went solid and either let AC through or more than ~15VDC.
>
> Hope this is a help.
>
> Matt
Thanks Matt. Seems simple enough. Hook one side of the transformer secondary to the correct "AC" spade on the regulator, ground the other side of the
transformer secondary to the Onan and see if the output measures better than 14VDC on my cheap multimeter. Then hook the "B+" lead to the battery and
the battery ground to the Onan and see if the battery voltage goes up.

Did I get it right?
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[ken harland]

> Ken,
>
> The regulator can be tested with a little bit of a haywire test stand. I used a door bell transformer to replace the alternator.
> But seriously, if you don't need it, leave it out.
> The Prestolite regulators are so primitive that they can't actually interfere with much, but why bother. I do need mine to charge the APU battery
> but I am still working on how to get around that without spending a fortune for copper and then having to find the path for the corner to corner
> run.
>
> Matt

Thanks Matt, mine appears to be working fine so I need to diagnose the problem with the control board. I'll spend some time on it tomorrow and report
back what I learn.
--
1978 Eleganza II

 

[Ken H.]

This whole thread has been so long & convoluted that I've probably missed
most of the point of it. So bear with me a moment while I try to clarify
the situation -- It may be easier to understand all this, and other board
functions, while looking at the schematic I redrew 15 years ago (having
only an MS in EE, I could barely follow the original):

http://www.gmcmhphotos.com/photos/data/5813/KH_Onan_Wiring1.pdf

Disregard the 4kW references -- 6kW is identical. And don't worry about
the missing regulator nor the added Pertronix -- they're not germane to
this (or 'most any other) discussion.

If I understand correctly, Ken's followed Duane's troubleshooting guide to
the point that he's found that there's less than 28 vac between pins 5 & 8
of the control board. If that's the case, IMHO, the alternator regulator
should be disconnected, IAW Duane's instructions. If that does not restore
the 28 vac at 5/8, the flywheel alternator winding and its connections
become suspect -- but the missing regulator no longer has ANYTHING to do
with the problem; forget it exists, or ever did, on a '78 coach.

Notice that the sole purpose of the 28 vac at 5/8 is to allow CR1 + R1 + C1
to create 10-11 VDC across C1 and, therefore, the coil of K2. With K2
activated, its NC contacts open, disabling K1 (the Start Relay) to ensure
that no one, thinking the silent Onan's not running, will activate the
starter. Simultaneously, K2's NO contacts close, activating the other
control board functions. SO, just as important as measuring the 28 vac is
measuring the 10-11 VDC across C1. If that's missing, ain't nothin' gonna
work. If the voltage IS there, then testing K2 is appropriate, etc.

As has been mentioned, if the flywheel alternator is defective, it can be
repaired; it's just a coil inside the flywheel and does NOT require Onan
removal to repair. But if the problem is serious enough to require more
than correcting a simple broken wire, it's much cheaper, easier, and just
as effective, to replace that coil with a 120/24 vac transformer. Wire the
primary of that transformer into the output of the 120 vac alternator (at
the circuit beaker?) and its secondary to 5 & 8, replacing the OEM wires
there Done. Unless you want to pull the flywheel, remove the coil, and
sell the copper.

HTH without adding to the confusion,

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc., etc.
www.gmcwipersetc.com

On Mon, Jan 16, 2017 at 10:00 PM, Ken Harland
wrote:

> > Ken,
> >
> > The regulator can be tested with a little bit of a haywire test stand.
> I used a door bell transformer to replace the alternator.
> > But seriously, if you don't need it, leave it out.
> > The Prestolite regulators are so primitive that they can't actually
> interfere with much, but why bother. I do need mine to charge the APU
> battery
> > but I am still working on how to get around that without spending a
> fortune for copper and then having to find the path for the corner to corner
> > run.
> >
> > Matt
>
> Thanks Matt, mine appears to be working fine so I need to diagnose the
> problem with the control board. I'll spend some time on it tomorrow and
> report
> back what I learn.
> --
> 1978 Eleganza II
>
>

 

[Ken B]

You have had a lot of well meaning but confusing repair suggestions without a thorough diagnosis of the problem. Before you go fixing things, you
need to determine exactly what is failing.

I suggest the following:
1. Jumper 5 and 9 together and get the generator running.
2. Read the AC voltage on 5 and 8. It should be somewhere around 28 Volts AC.
3. IF the voltage is incorrect, disconnect the regulator (which I think you have already done) and read the voltage again.
4. IF the voltage is still incorrect, with the engine running disconnect the field wire from pin 8 and read the AC voltage across pin 5 and the wire
removed from Pin 8.
IF the voltage is correct, you probably have a board problem. If the voltage is still incorrect you have a problem within winding located behind the
flywheel or the wires leading to it. WITHOUT THE ENGINE RUNNING, You can use an ohmmeter across pin 5 and the removed wire from pin 8 to look for an
open as you work on finding the problem.

Note: Like the regulator, a shorted C1 on the board will cause your low AC voltage symptom. Those capacitors on the board are very old, dry out, and
do short at times. I have replaced a few of them over the years.

--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Ken B]

Note: In the previous posting I used pin 5 instead of pin 11 because no components on the board are used for the reading. Either 5 or 11 could be
used but I recommend pin 5 so no board circuits are used when reading there.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[ken harland]

Thanks to both Kens for their comments. Let me summarize where I am...

- Genset wouldn't stay running
- Jumpered 5 to 9 and it ran fine, mistakenly believed I was only bypassing LOP
- Replaced LOP switch, problem still exists
- Tested voltage on pin 11, read 12.5 volts DC, mistakenly believed regulator failed
- Disconnected as instructed, voltage unchanged
- Was informed pin 11 voltage was AC, tested again and read 27.2 VAC
- Understand regulator is unnecessary and unrelated to voltage on pin 11, removed from circuit
- Will investigate relay on board not pulling in although correct voltage is present by examining board and components in detail and cleaning all
contacts then retest.

--
1978 Eleganza II

 

[jim miller]

Ken,
Not only are you bypassing the LOP switch with the 5-9 jumper but you are also bypassing the portion of the control board that uses the 28VAC signal from the flywheel alternator to determine that the engine has successfully started. On a working control board this 28 VAC signal is used to hold in a relay that keeps all the vital electrical functions of the engine energized and the same relay disengages the starter to prevent damage to the flywheel and starter bendix.

You didn’t give any description as to your control board’s appearance but here are the two considerations:

1. OEM control board. These are 40 years old and are notorious for component failures which manifest themselves in many different ways - one common failure mode is the “failure to run after successful start” behavior that you are describing. This board is no longer available from Onan but there are at least a couple fellows here on the net that repair them.

2. “DInosaur” aftermarket control board. These are of new manufacture but some of them have a flaw which only manifests itself on certain Onans. The failure is caused by the output voltage from the flywheel alternator being too high for a couple components on the board to endure - specifically a dropping resistor and the aforementioned relay that keeps the machine running after a confirmed start. I’ve written about this failure in the past and have provided some pictures at: http://www.jcmco.com/gallery/album30

!Note that not all Dinosaur boards seem to have this problem nor do they need the fix that I have developed!. In the majority of cases a new Dino board completely solves the problems associated with engine control and the boards are trivially simple to install.

In any case I’d suggest that based on your summary below that you purchase one of these boards from JimK and move forward.

Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH

>
> Thanks to both Kens for their comments. Let me summarize where I am...
>
> - Genset wouldn't stay running
> - Jumpered 5 to 9 and it ran fine, mistakenly believed I was only bypassing LOP
> - Replaced LOP switch, problem still exists
> - Tested voltage on pin 11, read 12.5 volts DC, mistakenly believed regulator failed
> - Disconnected as instructed, voltage unchanged
> - Was informed pin 11 voltage was AC, tested again and read 27.2 VAC
> - Understand regulator is unnecessary and unrelated to voltage on pin 11, removed from circuit
> - Will investigate relay on board not pulling in although correct voltage is present by examining board and components in detail and cleaning all
> contacts then retest.
>
>
> --
> 1978 Eleganza II
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Matt Colie]

> > A,
> > The regulators are just a little upgrade from flint-lock.
> > They are just at simple rectifier and clipping circuit. They can behave badly without a battery for output load.
> > When I have tested them, a bell transformer was just fine. Actually, those are cheaper now than they used to be so the unloaded output is
> > usually high from the specified 24VAC.
> > They are designed for 2 phase AC, but the Onan only uses half. I have tested both ways because my Kohlers do use the 2 phase, but it makes
> > little difference.
> > Essentially, you feed it AC and it outputs about 15VDC that is seriously ragged. If you have it on a battery when you power the regulator up,
> > you should see the battery terminal go up, but maybe not a lot. I have never tested to see what the single phase output is, but on a Kohler, they
> > can get close to 15 amp for a short time.
> >
> > I have only seen them go open. There has never been one of mine that went solid and either let AC through or more than ~15VDC.
> >
> > Hope this is a help.
> >
> > Matt
> Thanks Matt. Seems simple enough. Hook one side of the transformer secondary to the correct "AC" spade on the regulator, ground the other side of
> the transformer secondary to the Onan and see if the output measures better than 14VDC on my cheap multimeter. Then hook the "B+" lead to the
> battery and the battery ground to the Onan and see if the battery voltage goes up.
>
> Did I get it right?

Yes, It is that simple.
Matt

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Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit