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| Battery Question [message #153135] |
Thu, 15 December 2011 20:57  |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Does the house use the generator battery ? I disconnected the starting battery, and the and "house" battery. I had to grab something out of the coach and flipped the light switch and the light turned on. I thought the house only used the batteries up front, and the generator used that battery in the rear next to it.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: Battery Question [message #153138 is a reply to message #153135] |
Thu, 15 December 2011 21:07  |
zhagrieb
Messages: 676
Registered: August 2009
Location: Portland Oregon
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Ah, once again "the curse of the PO". Normally the lights in the house would be on the house batteries. Somehow the generator battery has become involved. Time for a little troubleshooting.
Glenn
Glenn Giere, Portland OR, K7GAG
'73 "Moby the Motorhome" 26'
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| Re: Battery Question [message #153139 is a reply to message #153135] |
Thu, 15 December 2011 21:10 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| Mr.RadioActive wrote on Thu, 15 December 2011 19:57 |
Does the house use the generator battery ? I disconnected the starting battery, and the and "house" battery. I had to grab something out of the coach and flipped the light switch and the light turned on. I thought the house only used the batteries up front, and the generator used that battery in the rear next to it.
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The 73's had different battery locations so when you say battery up front--I'm not convinced it is house or chassis. Also, It's possible that the battery in the rear is also connected to the "other" house battery.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Battery Question [message #153141 is a reply to message #153135] |
Thu, 15 December 2011 21:19 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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I'll have to investigate.
I have three batteries. One on the Onan in a sealed compartment.
Two upfront. The two upfront are both hooked to the isolator, one on each side.
Right now as I type both front batteries are out of the coach. But the lights in the house came on.
Stupid question, but if my dash board switch was switched to Boost, does that link all three batteries or just the two upfront. If it links all three then I'll check tomorrow to see if I just hit the switch by accident.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: Battery Question [message #153165 is a reply to message #153141] |
Fri, 16 December 2011 02:04 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| Mr.RadioActive wrote on Thu, 15 December 2011 19:19 |
I'll have to investigate.
I have three batteries. One on the Onan in a sealed compartment.
Two upfront. The two upfront are both hooked to the isolator, one on each side.
Right now as I type both front batteries are out of the coach. But the lights in the house came on.
Stupid question, but if my dash board switch was switched to Boost, does that link all three batteries or just the two upfront. If it links all three then I'll check tomorrow to see if I just hit the switch by accident.
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The Boost switch links only the two "upfront" batteries. (House and chassis.)
Is the coach plugged in? Your converter could be powering the house 12v circuits.
Other than that, check for some type of "jumper" from the Onan battery to the house circuits. Could be a PO added accessory like a prime button.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: Battery Question [message #153167 is a reply to message #153141] |
Fri, 16 December 2011 06:54 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| Mr.RadioActive wrote on Thu, 15 December 2011 22:19 |
I'll have to investigate.
I have three batteries. One on the Onan in a sealed compartment.
Two upfront. The two upfront are both hooked to the isolator, one on each side.
Right now as I type both front batteries are out of the coach. But the lights in the house came on.
Stupid question, but if my dash board switch was switched to Boost, does that link all three batteries or just the two upfront. If it links all three then I'll check tomorrow to see if I just hit the switch by accident.
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Mike,
As another owner of a '73 23', I can tell you that there is actually a connection between the house bank and the APU start battery. Records are unclear, but it is either a circuit breaker or a fusible link (unsure at this time) and mine was on the forward bulkhead of the APU compartment (under your right hand when you open the top access). I am fortunate to be the CO behind a very conscientious PO. He put in a switch in the electrics locker to disconnect the line between the house bank and APU battery.
The boost switch does not initiate a connection between the three batteries. It only connects the house and engine batteries.
Look for a wire from the buss bar for the house fuse bank that is on the forward bulkhead of the electrics locker that leads aft toward the APU box. This connection makes no sense if everything is working right and even less sense if it is not. A switch in the line is a good option - for emergency use only.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] Battery Question [message #153173 is a reply to message #153139] |
Fri, 16 December 2011 07:55 |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
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My aux and gen batteries are connected......first thing I'm going to do in
spring is straighten out that whole mess.
Ray
Ray & Lisa Erspamer
78 Royale "Great Lakes Eagle"
Center Kitchen TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
----- Original Message ----
From: Bob de Kruyff <NEXT2POOL@AOL.COM>
To: gmclist@temp.gmcnet.org
Sent: Thu, December 15, 2011 9:10:36 PM
Subject: Re: [GMCnet] Battery Question
Mr.RadioActive wrote on Thu, 15 December 2011 19:57
> Does the house use the generator battery ? I disconnected the starting battery,
>and the and "house" battery. I had to grab something out of the coach and
>flipped the light switch and the light turned on. I thought the house only used
>the batteries up front, and the generator used that battery in the rear next to
>it.
The 73's had different battery locations so when you say battery up front--I'm
not convinced it is house or chassis. Also, It's possible that the battery in
the rear is also connected to the "other" house battery.
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
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Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
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| Re: Battery Question [message #153179 is a reply to message #153135] |
Fri, 16 December 2011 09:48 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Terrific info, thank you all. I am loaded with enough info to trace this down. I think I have a game plan. Today I'm going to finish my battery tray, and if there is enough time I may try to trace it back. As long as I know it shouldn't be doing that, I'm in good shape!
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: [GMCnet] Battery Question [message #153197 is a reply to message #153179] |
Fri, 16 December 2011 12:31 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Michael,
Don't be too sure "it shouldn't be doing that". Even among unmodified
coaches, there are several variations of battery numbers, locations, and
connections. Multiply those by the number of PO's and their problems or
preferences, and the number of logical, reasonable combinations is very
large. It is entirely possible that you have a coach (house) battery up
front, on either side, wired directly in parallel with another in the rear,
which may, or may not, be connected to the generator; and, there may, or
may not, be a battery dedicated to the generator and connected to nothing
else.
If there's a house battery in the rear, hopefully it's protected with a
large circuit breaker (if it's OEM, it should be located on the aft wall of
its rear compartment and look like a hockey puck). And, it MAY connect to
the chassis (engine) battery when the boost switch is activated. If so, it
SHOULD have a solenoid relay near that "hockey puck" and connected to
bypass that current limiter during boost operation.
No one can reasonably evaluate your wiring via long distance; there are
simply too many variations. IMHO, what you need to do before attempting to
do before trying to trace the system is to recognize that there are three
basically independent systems, which may be temporarily, or permanently,
combined:
1. The engine (chassis) battery is normally charged by the engine driven
alternator, and is located on the driver's side beneath the passenger's
feet. But it may be connected by an isolator, combiner, boost switch,
jumper, or hard wired connection to one or more of the other systems.
2. The chassis (house) battery is normally charged from the 120 vac shore
power through the 120 vac to 12 VDC converter. In a standard OEM system,
it can also be powered by the engine driven alternator, through the
isolator. Just like the engine battery, it MAY be connected to the other
batteries also. There may also be more than one house battery, which may
not be collocated. And 6 VDC batteries in series may have replaced the OEM
12 VDC battery.
3. The generator battery was originally a separate battery, connected only
to the generator, which has a built in, 8 Ampere, charger. Later
production eliminated that battery and connected the generator to the house
battery.
Once you thoroughly understand those three systems (battery banks), then
you can concentrate on the various ways in which they may be connected, as
listed in 1., preceding.
As for your current "eerie" situation, I suspect you have a house battery
up front connected in parallel with another behind the generator. That's a
common situation, though not the best in terms of battery equalization.
Take a look at the various electrical treatises at www.gmceast.com.
Ken H.
On Fri, Dec 16, 2011 at 10:48 AM, Michael wrote:
>
>
> Terrific info, thank you all. I am loaded with enough info to trace this
> down. I think I have a game plan. Today I'm going to finish my battery
> tray, and if there is enough time I may try to trace it back. As long as I
> know it shouldn't be doing that, I'm in good shape!
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Ken Henderson
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www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: Battery Question [message #153229 is a reply to message #153135] |
Fri, 16 December 2011 21:07 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Well thank you again everyone for all the info. I figured it all out today.
Someone ran a wire from the Onan Battery to the hot side of the fuse house fuse panel. I'm not 100% sure why they did, but I disconnected it and everything worked like it should. However I'm going to keep the wire there but put a heavy on/off switch for it. Why? Well its nice to have just in case of emergency I'll always just have a flip of a switch to have a reserve battery to keep the lights on in the house. I'll isolate it.
Today I installed the (2) 6V and, (1) Starting battery. What a pain in the neck it all was but its done. Last thing I need to do is figure out a way to keep all the batteries tied down.
But (2) new oil cooler lines, (3) new batteries and everything is working great. I did find out that the Onan Battery was almost beat, so I'll have to buy a replacement, but no biggie. Its nice seeing two brand new 6v ers up front!
I mounted a push fan to the first transmission cooler. I'll wired it in next week. Then when going up steep grades I can flip the switch when needed! Having a GMC is like having the tree fort you always wanted when you were a kid!
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: Battery Question [message #153236 is a reply to message #153229] |
Fri, 16 December 2011 21:54 |
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I'm sure many on here will know what I mean; I just can't think of the name of the book that shows all the factory uprgrades and safety mods for the GMC. One of them shows a repair to the line that goes from the front battery through a big breaker to the 12v buss in the elec. compartment in the rear. It can short out and cause big problems and is only on the '73-74. It then goes to the Onan battery compartment. Mine has that and has the mod to correct the problem. I put a large diode in it so the large rear (Onan) battery stays charged. It only runs the 12v refrigerator(a separate fused direct line from the battery) besides charging the battery.
geo groth '73 260 Sequoia
Carson City Nevada 89703
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| Re: [GMCnet] Battery Question [message #153275 is a reply to message #153236] |
Sat, 17 December 2011 10:13 |
Mr ERFisher
Messages: 7117
Registered: August 2005
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One of them shows a repair to the line that goes from the front battery through a big breaker to the 12v buss in the elec. compartment in the rear. It can short out and cause big problems and is only on the '73-74.
here is one description
http://gmcmotorhome.info/chassis.html#Rear
I put a large diode in it so the large rear (Onan) battery stays charged. It only runs the 12v refrigerator(a separate fused direct line from the battery) besides charging the battery.
Since diodes fail shorted, and will only charge from the alternator, a combiner is better, since it will:
- charge all batteries from either source
- disconnect if there is a discharge problem
- is automatic, cannot forget to switch it off
- have no "diode" drop.
http://gmcmotorhome.info/batt.htm#diode
in this example, the combiner is shown connecting to a TOAD, but connecting to the generator is the same thing.
and
today, we do not remove the isolator, just put a combiner on it ;>)
http://goo.gl/91Qur
gene
--
geo groth '73 260 Sequoia
Carson City Nevada 89703
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“Give a man a fish; you have fed him for today --- give him a URL and -------
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Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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| Re: Battery Question [message #153294 is a reply to message #153135] |
Sat, 17 December 2011 13:27 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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I'm pretty good at remembering RV stuff usually! I think I'll still add a switch for the Onan Battery with a bright LED light when its on (charging) thats easy to see from anywhere in the coach. But I'll shut it off when parked for sure. I add a very heavy duty switch for the starting battery as well.
One thing I will do however pretty quickly is trace that wire from the house batteries to the 12v fuse panel in the rear. There is a lot of misc wiring I'd like to go thru before long. Right now I'm having zero issues, but there is a list of items that one by one I'd like to upgrade, and/or at least inspect.
Then the short list is; replace the onan battery today, and tie down my new batteries on the new tray, replace the lower radiator hose, and upper since then I'll know when they were both replaced. Make a screen door ( I have some new ideas about bending Sch 20 PVC and screening it) and make screens for the cockpit windows. I want to pull each wheel off and start learning about brakes (have several friends that know a lot and will teach me, I've never done a brake job or know what to inspect), and check brake lines and upgrade/replace them. The hose that goes from the power steering pump to the windshield wipers needs to be replaced as its rubbing against the nose of the coach its not leaking but I want to keep it that way. I want to take off the storage pod, AC, etc and heat coat the roof. Pull out the carpet and put in "wood" type floors, and replace the couch with a custom made one that is easily leveled when used as a bed. Then I'd like to figure out which chairs swivel for the cockpit since mine don't and I'd rather use that space better. Re-Felt my windows since they are HARD to open. Man the list goes on and on, and I'm not even done with it! LOL
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: Battery Question [message #153374 is a reply to message #153135] |
Sat, 17 December 2011 22:59 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Well Matt thats true. But why not. The wire is already there, and if I don't run the generator long enough to charge the battery I can flip the switch to charge it a bit from the alt if needed. Not really ever planning on needing it. If the switch is in the off position its like its disconnected anyway from the house and the normal setup for the onan. But flip the switch and theres just one last way to get a little more juice in case of power emergency.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: Battery Question [message #153480 is a reply to message #153135] |
Sun, 18 December 2011 19:50 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Yup did that as well. I can now by pass the isolator when I'm driving and switch the starting battery off when parked. I like over kill in many things I do.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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