| Battery Isolator/Boost switch [message #154249] |
Sat, 24 December 2011 07:46  |
MikeT
Messages: 225
Registered: November 2009
Location: Marine City, Michigan
Karma: 0
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Senior Member |
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Hello again,
77 Royale, No combiner. Both batteries up front with a third in Onan compartment. I understand the boost solenoid will tie the two batteries up front together for an engine jump, etc. Not really sure what the battery isolator does.
I currently only have one battery installed up front in the forward most position. Engine starts no problem. My problem is that the positive cable for the second battery up front, that is not installed, is HOT.
I purchased a new volt meter for Christmas but will not receive until tomorrow from Santa. I can then check if the boost switch is always on indicating a bad solenoid. What do I need to test on the battery isolator to insure that is good?
I would think the second battery positive cable should be COLD since there is no battery installed provided the solenoid and isolator are good. Should I be checking anything else.
How did I know it is Hot! While just hanging there not attached to a battery, the pos cable touched some metal and sparked.
Thanks for your help troubleshooting this.
Mike Thomas
Marine City, MI
77 ex Palm Beach
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| Re: Battery Isolator/Boost switch [message #154254 is a reply to message #154249] |
Sat, 24 December 2011 07:59  |
kingd
Messages: 592
Registered: June 2004
Karma: 2
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Senior Member |
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Mike, as Ken B. noted in the other post, unless someone has "messed" with your electrics, there should be an Isolator
that feed both the chassis and house batteries with the engine running. With only an isolator(a couple of doides on a heatsink)
the boost switch off and NO combiner, the coach.house battery wire should not be HOT.
DAVE KING
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
[Updated on: Sat, 24 December 2011 07:59] Report message to a moderator |
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| Re: Battery Isolator/Boost switch [message #154256 is a reply to message #154249] |
Sat, 24 December 2011 08:44 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| MikeT wrote on Sat, 24 December 2011 06:46 |
Hello again,
77 Royale, No combiner. Both batteries up front with a third in Onan compartment. I understand the boost solenoid will tie the two batteries up front together for an engine jump, etc. Not really sure what the battery isolator does.
I currently only have one battery installed up front in the forward most position. Engine starts no problem. My problem is that the positive cable for the second battery up front, that is not installed, is HOT.
I purchased a new volt meter for Christmas but will not receive until tomorrow from Santa. I can then check if the boost switch is always on indicating a bad solenoid. What do I need to test on the battery isolator to insure that is good?
I would think the second battery positive cable should be COLD since there is no battery installed provided the solenoid and isolator are good. Should I be checking anything else.
How did I know it is Hot! While just hanging there not attached to a battery, the pos cable touched some metal and sparked.
Thanks for your help troubleshooting this.
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I suspect the reason that terminal is hot is because that is coming from the battery in the back--those are probably hard wired together and the boost switch just connects that circuit to the chassis battery. You can tape it up or pull a terminal off the rear battery for now.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Battery Isolator/Boost switch [message #154263 is a reply to message #154249] |
Sat, 24 December 2011 11:03 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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| MikeT wrote on Sat, 24 December 2011 05:46 |
...
77 Royale, No combiner. Both batteries up front with a third in Onan compartment. I understand the boost solenoid will tie the two batteries up front together for an engine jump, etc. Not really sure what the battery isolator does.
I currently only have one battery installed up front in the forward most position. Engine starts no problem. My problem is that the positive cable for the second battery up front, that is not installed, is HOT. ...
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As you get advice from GMC owners keep in mind that you have a Royale (upfitted by Coachman) and MOST GMC'ers have GM upfitted coaches. While lots of things are the same there is quite a bit that Coachman did differently than GM. As a Coachman product owner, you will need to learn what areas are different so that you can "filter" your advice...
House wiring is one area that Coachman is different. (The Royales even more than the Birches.) The batteries on MOST Royales left the factory with a front mounted engine battery and front mounted house battery wired in parallel (through a #10 wire) with a rear mounted house/generator battery.
If a PO hasn't changed the wiring, the voltage seen on the disconnected positive cable is most likely from the rear "generator" battery or from your converter. (buzz box)
There are Coachman (and GM) wiring diagrams on bdub's site.
Note: This "Royale" battery set up "works" but is hard on house batteries. I would recommend using the later GM coaches as a guide to install a large rear house bank and a single front engine battery.
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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