60 AMP C/B

R

randy1

New member
Jul 5, 2007
1,979
0
0
I spent a rare cool April day working on an electrical issue on my 73 Painted Desert. The house side of the boost solenoid is connected to the 60A C/B
that feeds the house. When it is connected this way, it in essence has both batteries tied together and consequently they both deplete. If I move the
60A wire to the engine start side, then the engine starting battery has become both the house and starting battery and the house battery is just along
as a spare. How should I wire the 60A C/B so that it feeds the house off the house battery, but is separate from the engine starting battery.
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
My battery configuration is house and starting up front and the dedicated Genset battery in the back. I have an isolator and combiner as well as a PD
intellicharger.
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
Randy,

I'm confused: If the house battery is connected to one side of the boost
solenoid, and the chassis battery to the other, how can the house circuits
draw from the chassis battery IF THE SOLENOID IS OPEN?

The other scenario is logical: both batteries on one terminal will
certainly drain together.

What am I missing? I presume your '73 does have the latching selector
switch.

Ken H.

> I spent a rare cool April day working on an electrical issue on my 73
> Painted Desert. The house side of the boost solenoid is connected to the
> 60A C/B
> that feeds the house. When it is connected this way, it in essence has
> both batteries tied together and consequently they both deplete. If I move
> the
> 60A wire to the engine start side, then the engine starting battery has
> become both the house and starting battery and the house battery is just
> along
> as a spare. How should I wire the 60A C/B so that it feeds the house off
> the house battery, but is separate from the engine starting battery.
> --
> Randy
> 1973 26' Painted Desert
> Ahwatukee (Phoenix) AZ
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Not so sure this applies to 73 but on mine the CB is in series with the hot lead to the house batt. This protects the long cable. When you press the
Boost the 2 batteries are paralled at the firewall and a second solenoid contactor is energised back at the CB that shunts across the CB bypassing it
during boost.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
> Randy,
>
> What am I missing? I presume your '73 does have the latching selector
> switch.
>
> Ken H.

Ken,

Your confusion is understandable.

Yes, it does latch. At least all 73&4 had a normal (non-momentary) switch there.

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
 
> I spent a rare cool April day working on an electrical issue on my 73 Painted Desert. The house side of the boost solenoid is connected to the 60A
> C/B that feeds the house. When it is connected this way, it in essence has both batteries tied together and consequently they both deplete. If I
> move the 60A wire to the engine start side, then the engine starting battery has become both the house and starting battery and the house battery is
> just along as a spare. How should I wire the 60A C/B so that it feeds the house off the house battery, but is separate from the engine starting
> battery.

Randy,

Your coach is very much like mine, but the APU and its start battery are 3 feet farther.

Executive Summary: Leave it alone for the most part, but go to a pair of GC2s for a house bank. You only need a new battery tray.

I strongly suggest against your plan and for a number of very good reasons.

The first is that lead/acid batteries do not play nicely in parallel. So, you will not get the benefit of having twice the draw potential. With as
much resistance between them as you are setting up, they will NEVER balance out.
The other is that if one of the batteries should fault, one (no bets which) will explode.
Trailing along in third is the fact that you could now deplete both to the point that you cannot crank and fire the main engine without starting the
APU and using it to rebuild one of the batteries to a usable charge.

I did an awful lot of boat work before the depression. I converted a good number of racing sloops to performance cruisers. Many owners wanted to
stay with the electrics that they had. Most had a dual bank with an Off-1-Both-2 switch. I would get call (sometimes on VHF) what they could do when
both banks were down.

After we got them back to home moorings, the discussion would be restarted and to a case, I sold them on an isolated main engine battery. Now that
weight was not a critical factor, I could also sell them on a multi-jar house bank. I avoided multi-12V because of the above. When the subject could
not pass, the multi-12 were always isolated by breakers or fuses. (Avoid coming off primary power without current limiting protection.) None liked
the idea of a 4D (130#) or 8D (170#) battery as installing or removing same from a sailboat is not much fun at all. A guy can still carry a GC2.

You can fit the pair of GC2s in the front right, but you will need a bigger battery tray. You can buy one from a faithful supplier in Newark CA, or
use plywood and lay a cover of PE over it but still plan to replace it when you replace the house bank in about 8~10 years. Mine is 8 right now and
doing fine.

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
 
> > Randy,
> >
> > What am I missing? I presume your '73 does have the latching selector
> > switch.
> >
> > Ken H.
>
> Ken,
>
> Your confusion is understandable.
>
> Yes, it does latch. At least all 73&4 had a normal (non-momentary) switch there.
>
> Matt
I was going to suggest the boost solenoid was seized in the closed position. But the switch set in "boost" would do essentially the same thing.

Why hasn't anyone said in so many words "is your boost switch ON all the time?"
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"When I grow up I am going to be a curmudgeon."
 
I thought the boost was seized but it's not. When I remove the 60A wire, the batteries are separate, but the house gets no feed.

I have used GC2 batteries and they deplete almost as fast as the Deep Cycle, but are more expensive to replace.

Is the 60A C/B connected to the starting battery simply because the batteries are not charged identically and the combiner or PD unit has them
connected?
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
> I thought the boost was seized but it's not. When I remove the 60A wire, the batteries are separate, but the house gets no feed.
>
> I have used GC2 batteries and they deplete almost as fast as the Deep Cycle, but are more expensive to replace.
>
> Is the 60A C/B connected to the starting battery simply because the batteries are not charged identically and the combiner or PD unit has them
> connected?
There is supposed to be an isolator that connects the engine alternator to both chassis and house batteries. It is just two big diodes that keep the
batteries from being able to discharge each other. The boost switch connects the house battery in parallel with the chassis battery. The 60A CB
connects the house battery to the DC distribution block in the rear.

Take the 60A CB off the boost solenoid and put it on the house battery side of the ISOLATOR.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"When I grow up I am going to be a curmudgeon."
 
I have a combiner and an isolator, but removing the isolator doesn't seem to change things. There is still continuity across the solenoid which drains
the batteries. The wire off the 60A C/B is only long enough to reach the solenoid (and appears original) and couldn't reach the isolator. Perhaps
ditching the isolator and sticking with the combiner and PD charger is still a good idea, even if it doesn't fix this particular problem.

--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
The solenoid has two small terminals. One should go to ground. The other goes to the boost switch. Take a voltmeter and put one terminal to ground and check the small solenoid terminals. Do you get 12 colts at one of the terminals. Let us know and we'll give further instructions.

Emery Stora
77 Kingsley
Frederick, CO

>
> I have a combiner and an isolator, but removing the isolator doesn't seem to change things. There is still continuity across the solenoid which drains
> the batteries. The wire off the 60A C/B is only long enough to reach the solenoid (and appears original) and couldn't reach the isolator. Perhaps
> ditching the isolator and sticking with the combiner and PD charger is still a good idea, even if it doesn't fix this particular problem.
>
> --
> Randy
> 1973 26' Painted Desert
> Ahwatukee (Phoenix) AZ
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Download the wiring diagrams from http://www.bdub.net/wirediagrams/

Still seems to me that the boost solenoid is closed. That, or short circuited diodes in the isolator, would be the only things that can cause a house
load to drain the chassis battery. Those are the only two places that the two batteries could be joined.

Any other connections would be PO inflicted.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"When I grow up I am going to be a curmudgeon."
 
He also has a combiner and I have seen a number of them fail. Dan went through 3 of them himself. I would disconnect the combiner and get the coach
back to stock wiring BEFORE checking other things. Who knows how it is wired right now.

It would take a double diode short inside the isolator to cause this failure, so I doubt that is his failure. With the combiner out of the picture we
could trouble shoot what he has.

As a side note: there is a lead on the combiner that enables combining all of the time. This could be a combiner wiring issue or a combiner failure.
Disconnecting it temporarily will take it out of the picture.

The 60 amp CB is suppose to be in the house battery circuit to allow charging of the house battery while preventing a direct short inside the battery
from causing an explosion. Do NOT remove the CB, but wire it according to the GMC wiring diagrams.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
After isolating the combine, the isolator,the PD unit and every individual wire I could access, it appears that the solenoid is intermittent and
hanging up. When the combiner was reattached and it connected, there was continuity across the solenoid. when it was removed, the continuity remained
until the boost switch was cycled a few times then the sides of the boost solenoid separated.

--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
Have you installed a shiny new boost solenoid solving the problem? Also be aware there is a time delay circuit in most combiners to prevent the
relay from chattering in a feedback loop. Allow this to time out and unlatch before getting confusing meter readings. If batteries are fully topped
off, the high voltage surface charge can hold the relay closed even with no charge voltage present until things settle down. Of course on the Yandina
the green LED will indicate that.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
I replaced the solenoid probably 5 years ago when this similar issue first raised its head. I had lived with it by disconnecting the starting battery
everytime I parked for an overnight. I checked continuity across the solenoid immediately after re-energizing the combiner hoping I would see it
unlatch and re-latch and help isolate the culprit, but it had continuity regardless. I'll pick up a new boost solenoid and give it a try. This has
gotten me back to paying attention to the coach, during these last cool days at least.
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
 
There are intermittent duty solenoids whose purpose is for brief use, like
a starter on an engine, And there are continous duty solenoids that are
intended to be used in a constantly closed mode for long periods of time.
That is what the coaches used when they were built. However, some
solenoids fail and were replaced with intermittent duty ones by mistake.
That is perhaps what happened in your case. Jim Bounds and Jim K both have
the correct ones in stock. I don't know the exact part number for the
correct one.
Jim Hupy
Salem, Or
78 ROYALE 403

> I replaced the solenoid probably 5 years ago when this similar issue first
> raised its head. I had lived with it by disconnecting the starting battery
> everytime I parked for an overnight. I checked continuity across the
> solenoid immediately after re-energizing the combiner hoping I would see it
> unlatch and re-latch and help isolate the culprit, but it had continuity
> regardless. I'll pick up a new boost solenoid and give it a try. This has
> gotten me back to paying attention to the coach, during these last cool
> days at least.
> --
> Randy
> 1973 26' Painted Desert
> Ahwatukee (Phoenix) AZ
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
For something like this, it is important to get back to basics and use only the proper part. When mine fell apart, I checked with the manufacturer, Cole Hersee, and got the next size larger, continuous use rated. They won't sell direct, but with the CH part number, a quick look on Ebay took care of that. The one I installed was "Made in the USA" imagine that.

----- Original Message -----

From: "Randy"
To: gmclist
Sent: Wednesday, April 5, 2017 8:13:12 AM
Subject: Re: [GMCnet] 60 AMP C/B

I replaced the solenoid probably 5 years ago when this similar issue first raised its head. I had lived with it by disconnecting the starting battery
everytime I parked for an overnight. I checked continuity across the solenoid immediately after re-energizing the combiner hoping I would see it
unlatch and re-latch and help isolate the culprit, but it had continuity regardless. I'll pick up a new boost solenoid and give it a try. This has
gotten me back to paying attention to the coach, during these last cool days at least.
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ

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

Sounds like you've finally solved the problem -- the boost solenoid is
bad. Any switch carrying large loads is subjected to contact arcing and
burning, especially when opened those actions can cause the contacts to
weld together momentarily and even permanently. With easily opened
switches that damage can often be repaired. WIth a sealed device like our
boost solenoids, it's not worth the trouble. Replacements are readily
available, but be sure what you buy is rated for continuous duty, otherwise
it's likely to overheat and fail when you leave the Boost switch on for an
extended period.

Here's one source, but you can probably do better:
https://www.delcity.net/store/Insulated-Continuous-Solenoids/p_743392.h_817794

Ken H.

> After isolating the combine, the isolator,the PD unit and every individual
> wire I could access, it appears that the solenoid is intermittent and
> hanging up. When the combiner was reattached and it connected, there was
> continuity across the solenoid. when it was removed, the continuity remained
> until the boost switch was cycled a few times then the sides of the boost
> solenoid separated.
>
>
 
Why are these boost solenoids / relays failing? They are suppose to be continuous duty and are probably the least used electrical item on the coach.
I can not remember ever using mine.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
You must log in or register to reply here.
Get your shine on at www.cruzingear.co
GMCMI Fall 2026 Rally

Share this page

Share this page
Top Bottom
Back