No power from Coach Battery - P30 Chasis

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Well-known member
May 11, 2005
Riverton (SLC) Ut
I know there are is an endless supply of knowledge on this forum about the P30 chasis so after searching my owners manual endlessly, I realized I'd better go to the experts. I couldn't find anything that answered my questions after searching, so I'm going to ask everyone.

In my 95' Class A, on a Chevy P30 chasis, with a Chevy 454 I'm having some electrical problems. Thanks to the advice from this site, I found out a few months ago I had a bad alternator, which drained by coach battery. So I replaced the alternator and all was well. The first time I took it out afterward, I had a dead battery again. I assumed it didn't get enough of a charge, so I put the battery charger on. I went out to start the coach after about a month of it sitting, and I have absolutely no power to the dash. I don't even get dim lights. So I assumed the battery was bad and took it to Autozone to check it (Its a new battery). It checked out fine. So came home and installed it again, checked the ground and still I have NO lights to the dash. Out of curiosity I pushed the emergency start button to see if I could start it from the house batteries and everything lit up like a christmas tree.

I'm trying to isolate what would allow power to get to the coach using the emergency house batteries, but not come straight through using the coach battery?  I would suspect there is something like a fuse or a breaker, or something "hopefully" simple that I'm missing. I'm hoping with the vast knowledge around here, I can get some assistance.  If this sounds like something you have experience with, I would appreciate any advice, direction, or assistance that can be provided.

Thanks in advance for all your help, you guys are the best.
Several questions:

2. When you say coach battery do you mean chassis (or truck) battery?

1. Have you put a test light or voltage meter on the chassis battery while you are having problems. It still sounds like the chassis battery is dead. (you might check all batteries this way to make sure).

3. Most manufacturers provide a battery cut off switch for the coach (RV) battery and a few provide one for the chassis. Also someone may have installed one for the chassis battery as an aftermarket add on. One way to test this would be to put a charger on the chassis battery and see if the 12 volt systems on the chassis (lights, lighter, etc) work. If they do not you have the battery isolated or it is dead. (You could also  do this with jumper cables to the chassis battery from the coach batteries).


Thanks for the additional questions, I knew I would forget something.  Yes, the chasis battery is the one that I'm having problems with.  As for aftermarket addition of the batteries, I'm 99% certain these are all factory installed. 

As for jumping the chasis battery, I actually have a portable battery pack used to jump autos. I verified it had a full charge, and hooked it up to the cables from the chasis battery and I still got nothing. Again, I appreciate the additional questions, if there is anything else you can think of to check, please let me know.


Your brilliant. I knew this would be easy. I went back and re-read your comments for #3. It hit me, that I do indeed have a cut off for the chasis and house batteries. Luckily it is right by the entrance where the kids love to push buttons. I've had this happen on the House batteries before, but never on the chasis. So, I'll admit to being clueless on this one. It is all fixed, now I can go camping for the last time this year.

I knew it this could get answered by this group quickly. 

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