Forum Discussion

tpcollins's avatar
tpcollins
Explorer
Jun 16, 2017

Is my "boost assist" connected correctly?

I've been puling my batteries at the end of the season and occasionally charge them throughout the winter in my garage. But I want to make sure I have that starting boost cable attached the right way. The chassis batteries are color coded so they're easy to attach. The house batteries are not but I hook them up by the shortest must be the negative and the longer one is able to reach further to the positive.

But the boost cable seems a bit short too but I can stretch it to the positive side of the house batteries - is that correct? Thanks.
Class A
  • OLYLEN's avatar
    OLYLEN
    Explorer
    Jun 16, 2017
    normally the house and chassis batteries each have a ground to the frame. The house has two hot leads as does the chassis, the house one to the house and one to the boost solenoid and the chassis has one to the chassis side and one to the boost solenoid. The hot wire to activate the boost solenoid is usually from the chassis side. So if the chassis battery is truely dead there is no power to activate the boost solenoid and start the RV motor itself.

    LEN
  • DrewE's avatar
    DrewE
    Explorer II
    Jun 16, 2017
    Boost would go to positive assuming there's only one boost cable (which would be typical). The negative return is through the shared chassis ground.

    Whichever other wire is connected to chassis ground goes to negative. Whichever other wire is not connected to chassis ground but to fuses etc. goes to positive.

    Relying on length as a general rule is rather unwise; I don't think there's any defined consistency there. If you know it's correct for your particular RV, that's of course a different matter entirely. (For that matter, relying on colors being correct can be problematic as well; a battery cable may have been replaced, and the correct color may not have been handy when it was replaced.)

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