Batsome Report post Posted June 11, 2018 Recently my chassis battery died and I thought "no problem" as I have that trusted auxiliary start button. I pushed it and to my surprise...nothing! It has worked in the past but no more. Might anyone have any suggestions? Share this post Link to post Share on other sites
manholt Report post Posted June 11, 2018 Acid batteries or AGM? My first thought, you have acid and when did you last look at water level in all batteries? Second, are you on shore power off any amperage and is it delivering current to coach? Check your CB for any that has tripped and the CB on Inverter/converter! How old are your house batteries? Would help to know make, model and year off your coach! Share this post Link to post Share on other sites
wolfe10 Report post Posted June 12, 2018 In many coaches the power to the "battery boost/combine switch" comes from the chassis battery. If not enough voltage, boost solenoid/relay will not close to combine batteries. Best answer is to use an auxiliary charger to bring the chassis battery up. Share this post Link to post Share on other sites
Batsome Report post Posted June 12, 2018 Thanks for the information. Share this post Link to post Share on other sites
wolfe10 Report post Posted June 12, 2018 Locate the boost solenoid. Check voltage at the small "sense" wire that receives 12 VDC when the switch is pushed. Because it takes very little current to close the solenoid, you could use a small jumper wire from the house battery lug of the solenoid to the sense terminal. Be aware that that would be very hard on both the solenoid and the house battery, as it would cause a very large amount of current to go from the charged battery through the solenoid to the deeply discharged battery. Said another way, only do this in an emergency. Best advice is still to use an auxiliary battery charger to bring the discharged bank up. Share this post Link to post Share on other sites