Forum Discussion

JnJnKatiebug's avatar
JnJnKatiebug
Explorer
Dec 02, 2013

Battery Boost Won't Work

Went out to start the MH yesterday and the batteries were low. Hit the boost switch and nothing. I put my jumper cables from the house batteries over to the starter batteries and it cranked right up. I used the boost switch late last summer and it worked fine. I have not had time to check it out. Where would be the best place to start looking for the problem? Is there a fuse?

Batteries are six years old now and they are down after 3 to 4 weeks of sitting even with the disconnect turned off. Probably need batteries in the spring but for now I am leaving the charger/maintainer on it.
Class A

4 Replies

  • Ivylog's avatar
    Ivylog
    Explorer III
    Dec 02, 2013
    If you have a BigBoy relay in the rear electrical box, check that you can hear it click when someone hits the boost switch. If it clicks then the contacts need to be cleaned/filed as you can take it apart. Unhook both sets of batteries as it's a tight fit getting it out and you do not need to arc weld anything. If it does not click then call Monaco for wiring help.
  • crasster's avatar
    crasster
    Explorer II
    Dec 02, 2013
    Assuming you have a boost relay, the house batteries must have enough juice in them (crank amps) to switch the relay or to kick on the starter motor.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Dec 02, 2013
    Hi,

    If the chassis batteries were totally flat they might not be able to energize the boost relay.

    The relay may have burned contacts.

    Can you hear the relay activating when you press the boost switch?
  • The_Texan's avatar
    The_Texan
    Explorer
    Dec 02, 2013
    It is the relay located in the battery compartment, on the back wall. It is a Trombetta model 010, with copper contacts. Make sure you replace it with the 020 model, which has silver alloy contacts.

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