Quadrajet Electric Choke: 12 volt ign source?

C

charles boyd

New member
Jul 8, 2007
3,462
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Sir, i wire mine to center post of battery isolator. Also use an inline fuse. Only has volts with engine running and has doesn't rob any from other
circuits.

> For those of you that have already converted over to an electric choke, where did you pick up 12 volts from an ignition keyed source? The
> distributor does not provide 12volts because of the resistance wire. I thought I read that electric chokes pull about 3.5 amps and perhaps I could
> run a wire to the alternator with a 5 or 10 amp fuse. Suggestions?

--
C. Boyd
76 Crestmont
East Tennessee
 
Same as wiring to the alternator. The output wire of the alternator connects directly to the center terminal of the isolator. That is where I
connected my electric choke also.
--
Roy Keen
Minden,NV
76 X Glenbrook
 
What kind of ignition do you have? Points or HEI?

If you have HEI then power it off of the same +12 connection as distributor.

If you have a points distributor, there is a dropping resistance wire in series with the coil and you need to power the choke just before the
resistance wire.

There is a connection between the 20 ga. resistance wire (pink / black) and the regular wire (18 ga. black) on top the engine. Follow the resistance
wire from the coil wire back toward the front of the engine and find where it connects to a black wire that continues on to the terminal BK under the
passenger hood. Attach your new choke wire to that junction of the resistance wire and the regular wire. It sounds more difficult than it really is.

Here is a thread from last January where we were discussing this connection for a different reason.

http://www.gmc.mybirdfeeder.net/GMCforum/index.php?t=tree&goto=351835&rid=12&srch=resistance+wire

I do not like the isolator connection solution because if the alternator ever quits you can not drive on the battery, or boost switch using the Onan.
I doubt you will even make it to the next interstate exit before the choke closes and kills the engine.

The choke on mine draws about 1.5 amps
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Ed,

As your coach is a 74 and hopefully not gotten an HEI installed, here are the options:

KenB said he does not like the isolator center terminal because if your alternator goes down, the engine will shut down because it got choked to
death. This does have some merit.

I don't like tying it to ignition-on power (the actual ignition circuit is too close to maximum load in a points engine system) because that is
actually the accessory circuit and I have had to sit with that circuit live for other reasons and if cold, the choke would open. I even added a diode
to the choke circuit to get a opening rate I liked. Once dialed in (took two tries), it works like a champ.

There is a third not mentioned above, that is if you buy the kit that has a thermal switch that you can mount on the thermostat housing. Then it
powers the choke heater when the engine gets hot. I have never put one on a GMC, but used these other places and they can be set up to work right.

Side note....
I said hopefully not HEI because if it is, I will strongly suggest that you carry a kit to replace all the important Olds engine parts in an HEI
distributor. If you replace the points with A Pertronix 1181LS, that is a very reliable mod. (You can put the removed points and condenser in a jar
and carry then as spares if you are paranoid.)

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
> Thank you for your response. I have points but will be converting to Dick Paterson Pertronix distributor within the month. I was having a
> quadrajet issue of flooding after a local carb rebuild but couldn't seem to get it corrected by the carb rebuilder. Dick says it's a
> float/needle/seat problem but after replacing quadrajet, I put a straight edge across bottom of the original carb and the base is warped - high in
> center. Tearing it down today to check the rest of the carb. Meanwhile, replacement carb (reman by Dick) has an electric choke that needs 12 volts.

Ed,

Looks like we are posting at about the same time - I am eastern so it is only about 9AM here.....

What Dick says should be held to.

Your local rebuilded should have done that flatness check before he accepted the job. According to Dick, that is a result of people reefing down the
mounting fasteners. The need only be snug.

Oh, I also forgot what you asked about the isolator.
It is that finned aluminum thing under the right hood. It should have three terminals and the center is the output of the alternator.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
Matt, when they install that Pertronix mod, do they eliminate the ignition resistor (nichrome wire)?? I do not think so. If the nichrome wire is
still in use, then then what I said about finding that connection still should apply Petronix or not.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
> Ed,
> Side note....
> If you replace the points with A Pertronix 1181LS, that is a very reliable mod. (You can put the removed points and condenser in a jar and carry
> then as spares if you are paranoid.)
>
> Matt

For those considering a Pertonix conversion, this is a copy/paste of a post I did a while back. I repost it here because it is worth noting.

The points type distributor I have for my 73 Cad 500 needed rebuilding. So I sent it to Dick Paterson. He replaced the points system with the
pertronix 1181 and recurve the distributor. That was in 2005. Last summer, while doing some work on the FI that I have, it suddenly refused to start.
After some diagnosis, finally found it had no spark. The 1181 has a pick-up and a ring of magnets that go under the rotor. One magnet dislodged and in
turn scrubbed the electronic eye until I had a total ignition failure--complete with coil boiled out. Called and talked with Dick and he said that
they had problems with the 1181 Magnet ring, that I should order the 1181ls (LS is for Lobe Sensing), which does not have Magnet ring. I ordered the
"Flamethrower" 40011 as the matching coil. Got them from Summit. They had the lowest price and quickest shipping. (next day) Works fine...no moving
parts accept the lobes. With the 1181ls you take the points and condenser out, and drop the 1181ls pick-up in it's place. Takes about 5 minutes. Very
easy install. Most GM points type distributors use common parts, so the 1181ls should work in your Olds distributor. JWID
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Ken, with when
Under normal conditions using spliced the wire that feed the HEI is very
good.
However lot if the wire has been spliced with smaller wire and we have run
into poor distributor and choke issues. Again when one confronts all type
mods it is trusting.

On Sun, Mar 29, 2020 at 7:52 PM Larry via Gmclist
wrote:

> > Ed,
> > Side note....
> > If you replace the points with A Pertronix 1181LS, that is a very
> reliable mod. (You can put the removed points and condenser in a jar and
> carry
> > then as spares if you are paranoid.)
> >
> > Matt
>
> For those considering a Pertonix conversion, this is a copy/paste of a
> post I did a while back. I repost it here because it is worth noting.
>
> The points type distributor I have for my 73 Cad 500 needed rebuilding. So
> I sent it to Dick Paterson. He replaced the points system with the
> pertronix 1181 and recurve the distributor. That was in 2005. Last summer,
> while doing some work on the FI that I have, it suddenly refused to start.
> After some diagnosis, finally found it had no spark. The 1181 has a
> pick-up and a ring of magnets that go under the rotor. One magnet dislodged
> and in
> turn scrubbed the electronic eye until I had a total ignition
> failure--complete with coil boiled out. Called and talked with Dick and he
> said that
> they had problems with the 1181 Magnet ring, that I should order the
> 1181ls (LS is for Lobe Sensing), which does not have Magnet ring. I ordered
> the
> "Flamethrower" 40011 as the matching coil. Got them from Summit. They had
> the lowest price and quickest shipping. (next day) Works fine...no moving
> parts accept the lobes. With the 1181ls you take the points and condenser
> out, and drop the 1181ls pick-up in it's place. Takes about 5 minutes. Very
> easy install. Most GM points type distributors use common parts, so the
> 1181ls should work in your Olds distributor. JWID
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
Can you throw a part number for that heat driven choke?
Thanks

--
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
 
Just a heads up. I pulled off the electric choke that came on the carb and the spring is wound in the opposite direction. I would guess I could just
flip the spring around on the new electric choke but for now I will use the choke on the carb.
--
Ed Clerkin | 1974 GMC Canyon Lands 26’
 
That is interesting. I have never seen one that goes the opposite way but it makes sense that they would make one for other applications. If the
spring is easily reversible, I would do that. Maybe also some PO had it apart and put it together backwards. It is just a bi-metal spring that
expands and contracts when heat is applied and removed.

A day or 2 ago someone put up a link to electric chokes. I see that that CU1121 here and CU1122 appear to be the same but rotate in the opposite
directions.
https://www.carburetor-parts.com/Electric-Choke-Conversion-Kit-CU1122_p_4542.html
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
> That is interesting. I have never seen one that goes the opposite way but it makes sense that they would make one for other applications. If the
> spring is easily reversible, I would do that. Maybe also some PO had it apart and put it together backwards. It is just a bi-metal spring that
> expands and contracts when heat is applied and removed.
>
> A day or 2 ago someone put up a link to electric chokes. I see that that CU1121 here and CU1122 appear to be the same but rotate in the opposite
> directions.
> https://www.carburetor-parts.com/Electric-Choke-Conversion-Kit-CU1122_p_4542.html

I figured it was reversible and their sales staff replied to me with 1121 not 22. Go figure. BTW, I put a volt meter on the center terminal of the
battery isolater and I am seeing voltage with the ign key off. Is this normal? If I hook up the choke to that terminal, it will send voltage to the
choke and heat it up since the choke metal plate inside cover grounds to the carb. Confused.
--
Ed Clerkin | 1974 GMC Canyon Lands 26’
 
Our shop ran into that reverse coil.
I basicly let my guys know that they were not doing it right.
When I put my hands on it,I found it was backward.
Blaime the Communist Chinese .

On Mon, Mar 30, 2020 at 7:56 PM Ed Clerkin via Gmclist <

> > That is interesting. I have never seen one that goes the opposite way
> but it makes sense that they would make one for other applications. If the
> > spring is easily reversible, I would do that. Maybe also some PO had
> it apart and put it together backwards. It is just a bi-metal spring that
> > expands and contracts when heat is applied and removed.
> >
> > A day or 2 ago someone put up a link to electric chokes. I see that
> that CU1121 here and CU1122 appear to be the same but rotate in the opposite
> > directions.
> >
> https://www.carburetor-parts.com/Electric-Choke-Conversion-Kit-CU1122_p_4542.html
>
> I figured it was reversible and their sales staff replied to me with 1121
> not 22. Go figure. BTW, I put a volt meter on the center terminal of the
> battery isolater and I am seeing voltage with the ign key off. Is this
> normal? If I hook up the choke to that terminal, it will send voltage to the
> choke and heat it up since the choke metal plate inside cover grounds to
> the carb. Confused.
> --
> Ed Clerkin | 1974 GMC Canyon Lands 26’
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
NO, it is not normal but try it again with a small load on it. Do you have a test light that could load it some and then take another voltage
reading.

What voltage were you reading when you were on there?
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
> NO, it is not normal but try it again with a small load on it. Do you have a test light that could load it some and then take another voltage
> reading.
>
> What voltage were you reading when you were on there?

Voltage was all over the place 8-12 volts then 0 then back again. I am going to replace the butteries in the volt meter first then retest. The same
thing happened with this same voltmeter when I was checking the courtesy light in the dinette by the door step and in fact it showed negative voltage.
Meter is new but may have a problem. I may have to pull out my trusty Sun analog meter. I do have a test light I can try that will put a load on it.
--
Ed Clerkin | 1974 GMC Canyon Lands 26’
 
Digital volt meter is not working. I hooked up my analog volt meter and it reads 0 voltage. Time to attach wire for choke then test.
--
Ed Clerkin | 1974 GMC Canyon Lands 26’
 
> Digital volt meter is not working. I hooked up my analog volt meter and it reads 0 voltage. Time to attach wire for choke then test.

Great.

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