| Hmn (mystery)drain on power system? [message #70678] |
Tue, 12 January 2010 19:43  |
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gmcdude76
Messages: 102
Registered: December 2009
Location: Northern Ca
Karma: 1
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Senior Member |
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When i bought it i had it inspected and told it had a slight drain
that wouldent effect the batterys.the last few months i have been working and trying to get a baseline for how the po had it set up.i have tried to clean any wireing disconnected cbs radios etc.
Still havent been able to isolate it.today i replaced the battery isolater.i read other posts that said they last about 8 years.mine sat for about that long.i had the batterys(house)checked by 3 shops and no one cought they both had dry cells.
I have since filled them and they hold just enough charge but not able to turn over my generator.the batterys are probally that old as well.i have tried to isolate anything that was installed after market to find the problem.
I just havent gotten out a tester and start running the circuits.ive been edcuating myself on whats what and how its connected but so far i am striking out.
Another question is when you hook up an isolater the po had a switch inline a power tap or positive battery post then the isolater.i will post some pictures i am unaware what the switch is for.it has a lot of leads and is tied to tne isolater and the house batterys and the engine battery.i thought this is an odd arrangement.but since i wasent able to deal with the actuall owner i have no clue as to what he did or why.
if needed ill post a photo of the switch.but its inline with the batterys power post(positive) then the actuall isloater is the basic set up?
Thanks for any input?
(btw your off topic lol)
Gmc76Birchaven 23'94947
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| Re: Hmn (mystery)drain on power system? [message #70695 is a reply to message #70678] |
Tue, 12 January 2010 21:38  |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
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| gmcdude76 wrote on Tue, 12 January 2010 17:43 |
Still havent been able to isolate it.today i replaced the battery isolater.i read other posts that said they last about 8 years.mine sat for about that long.i had the batterys(house)checked by 3 shops and no one cought they both had dry cells.
I have since filled them and they hold just enough charge but not able to turn over my generator.the batterys are probally that old as well.i have tried to isolate anything that was installed after market to find the problem.
Another question is when you hook up an isolater the po had a switch inline a power tap or positive battery post then the isolater.i will post some pictures i am unaware what the switch is for.it has a lot of leads and is tied to tne isolater and the house batterys and the engine battery.i thought this is an odd arrangement.but since i wasent able to deal with the actuall owner i have no clue as to what he did or why.
if needed ill post a photo of the switch.but its inline with the batterys power post(positive) then the actuall isloater is the basic set up?
Thanks for any input?
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Hard to answer much from your description but first thing you will need to do is to replace the batteries. Once any cell is completely dry, the battery has been completely trashed. They will never hold a charge, or be usable.
If you could post a photo of the "switch" and wiring we may be able to help you understand what it might have been for. PO's do some amazingly crazy things, and it might be something that you will be best to take out and go back to the original GMC design, which is surprisingly good. Someone on the net (the collective we) may be able to help you out there.
Rob Allen
former owner of '76 x-PB
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| Re: Hmn (mystery)drain on power system? [message #70697 is a reply to message #70678] |
Tue, 12 January 2010 22:20 |
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gmcdude76
Messages: 102
Registered: December 2009
Location: Northern Ca
Karma: 1
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Senior Member |
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One thing i forgot to ment is my geneator light would glow all the time with the key or the engine running.now after changing the isolater the gen light still stays on but is alot brighter.i am just trying to avoid the cost of new batterys if possible.they seem to be good with fluid in the cell.it would be nice to find the drain.without spending a fortune in the process.this is on a shoestring budget for now.if it aint broke dont fix it.
Thanks
Gmc76Birchaven 23'94947
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| Re: [GMCnet] Hmn (mystery)drain on power system? [message #70734 is a reply to message #70678] |
Wed, 13 January 2010 14:18 |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
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Senior Member |
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Hi Don
Nice looking coach.
When I purchased mine in 2006 and got it home, I had severe drains on the batteries. The previous owners had turned the electrical system into a complete nightmare with more after market stuff, bells & whistles, etc. After weeks of trying to understand it I finally literally got so mad I ripped off ALL of the extra stuff and brought the whole under hood electrical back to OEM. Then I started going through the rest of the coach. I think since I've owned it I've ripped out 500 feet of wire, it was an incredible mess.
I now have NO drains on any of the batteries. The last BIG item I found was the electric choke, it was wired direct and not through the ignition switch, so it was on whenever the coach sat.
Here's my recommendations:
1. Very first thing to do, install battery quick disconnects. These are what I installed, fairly inexpensive. http://www.summitracing.com/parts/PCO-5575PT
2. With those, whenever I was not using the coach, I just disconnected all batteries.
3. Starting going through ever circuit and eventually you'll find all of the issues and problems.
4. Inexpensive meters are available that you can clamp over the battery line that tell if there is a draw or not.
Ray
Ray & Lisa Erspamer
78 Royale Center Kitchen
The Malosco Cruiser (TZE368V101144)
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
________________________________
From: Don <mr_donberman@yahoo.com>
To: gmclist@temp.gmcnet.org
Sent: Tue, January 12, 2010 7:43:57 PM
Subject: [GMCnet] Hmn (mystery)drain on power system?
When i bought it i had it inspected and told it had a slight drain
that wouldent effect the batterys.the last few months i have been working and trying to get a baseline for how the po had it set up.i have tried to clean any wireing disconnected cbs radios etc.
Still havent been able to isolate it.today i replaced the battery isolater.i read other posts that said they last about 8 years.mine sat for about that long.i had the batterys(house)checked by 3 shops and no one cought they both had dry cells.
I have since filled them and they hold just enough charge but not able to turn over my generator.the batterys are probally that old as well.i have tried to isolate anything that was installed after market to find the problem.
I just havent gotten out a tester and start running the circuits.ive been edcuating myself on whats what and how its connected but so far i am striking out.
Another question is when you hook up an isolater the po had a switch inline a power tap or positive battery post then the isolater.i will post some pictures i am unaware what the switch is for.it has a lot of leads and is tied to tne isolater and the house batterys and the engine battery.i thought this is an odd arrangement.but since i wasent able to deal with the actuall owner i have no clue as to what he did or why.
if needed ill post a photo of the switch.but its inline with the batterys power post(positive) then the actuall isloater is the basic set up?
Thanks for any input?
(btw your off topic lol)
--
http://donsgmcdudes76photos.shutterfly.com/
Gmc76 Birchaven transmode 260/Carson Toyhauler/Burgman 400
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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: [GMCnet] Hmn (mystery)drain on power system? [message #70737 is a reply to message #70734] |
Wed, 13 January 2010 14:34 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
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>One thing i forgot to ment is my geneator light would glow all the time with the key or the engine running.
One of (several) cause of the generator light being on while the engine is running is a shorted positive diode inside the alternator, which will also cause a drain on the engine starting battery. With the "help" from the previous owner, that might only be one of your problems though.
Craig Lechowicz
'77 Kingsley, Waterford, MI
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| Re: Hmn (mystery)drain on power system? [message #70738 is a reply to message #70678] |
Wed, 13 January 2010 14:52 |
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gmcdude76
Messages: 102
Registered: December 2009
Location: Northern Ca
Karma: 1
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Senior Member |
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Hello,
Mr. ERFisher,had posted a link that was very helpull.i will follow some of the suggestions.such as installing an apc cable.checking the fuse and also it stated that a bulliton from gmc back in the day.that 76 or later has a inhearent defect that the light would stay on.so i may not actually have a drain. and as one mentioned that once the cells have drained there usually bad batterys from that point.there was a couple of fixes ill try.
But one thing is i am not 100 percent sure what a buz box is or does.i think there used to charge or maintain your batterys.there was such a "box" connected to the engine battery.i disconnected it as well as the light thats under the hood.the lines to it looked pretty rusted and frozen.
I am also tracing and removing any added on wireing thats not oem or gm installed.i had also removed the PO sterio system and the main line for the power amp etc.is still going somewhere.its under the drivers seat and id have to climb uner the coach to trace them.
But i am suspecting that light may not show a drain.i think the shop i took it to knot a gmc was totally inept in there inspections.i have found several prob they should of found.but as long as its not a major repair i dont mind fixing and learning this stuff.
Thanks for the help.
Gmc76Birchaven 23'94947
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| Re: Hmn (mystery)drain on power system? [message #70740 is a reply to message #70738] |
Wed, 13 January 2010 15:03 |
tphipps
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
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Senior Member |
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"Buzz Box" affectionately refers to the OEM installed house battery charger, generally found under the sink. They are ancient in design and "buzz" when operating. buzzing is caused by the transformer vibrating internally when operating. These chargers have the reputation of over-charging and boiling over the house battery. Most of us have replaced these with modern 3 stage chargers that will not boil out the house battery. Progressive Dynamics and others make them. Occasionally, you can purchase a re-built one from the manufacturer, if money is a question.
This is an easy change over, wires just swap over and your batteries will be happy. Buzz boxes are always on, when you are on either the generator or shore power. The modern types check the stages of charge and only charge the house battery when they need it. They also have a very low charge capability, to keep the battery up, without damage.
Hope this helps.
Tom Phipps,
75 GMC Ex-Avion
with PD45 charger
2012 Phoenix Cruiser model 2552
KA4CSG
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