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TC_Z's avatar
TC_Z
Explorer
Jan 12, 2015

Battery Boost Not Working

We have a Winn 2007 Voyage. We camped recently plugged in at a state park. My DW used the driver's seat to do her cross-stitching and used the driver's dome light over her shoulder. Well when we got ready to leave the MH wouldn't start - click click click. I now realize that the driver's dome light is likley on the engine battery not the converter or house batteries so assume it drained the engine battery. No worries, I will use the battery boost switch. Well, I held the boost switch in and it made zero difference - click click click. I tried several times with no luck. Thankfully we had towed our Jeep, had jumper cables and we were able to jump start the engine and get home.

I replaced the engine battery 2 yrs ago, the cells have sufficient water. Any ideas what my problem might be?
- Is the boost solenoid bad? How do I check it?
- Am I supposed to hold the battery boost switch for several minutes before I try to start?
- Is the power for the battery boost switch from the engine battery or the house batteries?
- other?

Any advice how to trouble shoot would be appreciated. If MH is not dependable my wife gets nervous that we will get stuck somewhere, me too for that matter!

Many thanks....
Class A

15 Replies

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  • crasster's avatar
    crasster
    Explorer II
    Jan 12, 2015
    I don't know how it works on all coaches, but on my bounder - my generator starter is much smaller than the truck. If I crank the generator on first, it supplies just a bit more power to the batteries and sometimes can crank the engine rather than just hearing a click. On my other Class C (Toyota) this does not work like that. I have to run the generator giving a fresh charge to the house bats, turn it off, then sometimes it will give enough "fresh juice" for the truck to start.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Jan 12, 2015
    Hi,

    To prevent this from happening again add a Trik-l-Start so the chassis battery will charge from the converter.
  • Artum_Snowbird's avatar
    Artum_Snowbird
    Explorer
    Jan 12, 2015
    If you have an opportunity to try starting using jumper cables from the house battery to the chassis battery, try that.

    Your boost switch might be working fine, but you could easily have a weak connection in the heavy wiring from house batteries to the boost switch, and then on to the chassis battery. Using the jumper cables and seeing it that makes a difference will give you a clue or two where the problem might be.

    When using the jumper cables, first just connect the positive to positive. If it starts, the positive line is the problem and your ground is good. If not, then connect the negative cable only. If it starts, your ground connection is the problem, and the boost switch is working properly.
  • wolfe10's avatar
    wolfe10
    Explorer
    Jan 12, 2015
    Don't know the wiring of your coach, but it is possible that voltage to activate the boost switch comes from the chassis battery. If so, and the chassis battery is dead, there may not be enough voltage to close the boost relay.

    If this is the case, use a jumper wire (small gauge is fine-- you will be powering less than one amp) from the house battery terminal of the boost solenoid to the positive signal terminal (will be a small wire/terminal).

    Once both banks up, you can check the solenoid, and it should be working (again, if my speculation above is correct). If you need advice on how to verify it, let us know.

    Long term, you need to make arrangements for the chassis battery bank to be charged (assuming this was not OE).
  • enblethen's avatar
    enblethen
    Nomad
    Jan 12, 2015
    If you hear the relay click, you are getting control power to it.
    You need to locate the relay, then check each side with a volt meter. They may not read the same or should not read the same.
    There should be chassis battery voltage on one side and coach battery power on the other. This is on the large terminals. If no power is seen on one of the terminals there is an open conductor or bad connection between it and the associated battery.
    Then have a helper hold the switch in to operate the relay. The relay large terminals should read the same. If not the relay is bad.

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