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Tom_Barb's avatar
Tom_Barb
Explorer
Jun 05, 2013

Chassis battery issues

The Coachis a 2000 Newmar with a Spartan chassis.

we tried to start the 8.3 cummins after 2 weeks on house power, and it cranked slow, did the boosted start and it started, OK but now the yellow check engine light is on.

Allowed the engine to run for about 10 minutes (good oil pressure and temps) and shut it down, waited about 2-3 minutes and started it again, no boost, and no light.

we took it camping 6 hours drive, camped 5 days, started the coach with no problems no lights and drove it home.

2 weeks setting on house power and the coach did the same thing, slow cranking until you boost it with house battery bank. and then the check engine light, run it 10 minutes and do the restart, no need to boost, and no light.

the batteries are the group 31 jell cell 2 12 volt in parallel no service type and 5 years old…

new battery time ?

17 Replies

  • I spoke with a couple of DP owners regarding chassis battery charging when connected to shore power and was informed that their chassis batteries were only charged by the engine alternator and they had to use a battery charger/maintainer plugged into a 110vac outlet when connected to shore power to keep their chassis batteries charged. Don't know if all DP's are that way though.
  • The isolater/relay is normally used to auto connect the 2 battery banks together when the alternator is putting out voltage. This charges the house bats as you drive.
    Many motor homes are delivered from factory with no automatic means to charge chassis bats when connected to shore power.
  • You need to look into your inverter setup specifically, but you could have a bad battery isolator/relay that is no longer allowing the chassis to charge.
  • Mine did the same thing at 5 years old. Put new batteries in and all is well. more b
  • Hi,

    Check the charging circuit from the "house" to the chassis while on shore power. Clearly it is non functional.
  • pianotuna wrote:
    Hi,

    Add an Amp-l-start

    Then the shore power will charge the chassis batteries.


    My Inverter does that,,, or should I say it always has.