abyrd Report post Posted December 29, 2015 My wife and I upgraded to a 2004 Holiday Rambler Endeavor about four years ago and thoroughly enjoy the unit, we previously had owned several class A and C motorhomes over a 30 year period previous to our upgrade. The only means to charge the coach batteries on the Endeavor is with the charger/converter which require shore power or running the generator, all previous owned motorhomes had an isolation relay that was energized when the main engine was running and the chassis alternator provided a means to charge the coach batteries when underway. I have a full set of electrical schematics and owner manuals for the Endeavor and system design only allows the paralleling the coach and chassis battery banks via of a momentary contact switch located on the dash. This provide a means to "jump start" your main engine from the chassis battery bank. I am considering installing a BLUESEA ACR that will all the coach battery bank and the chassis battery bank paralleled at all time but will automatically isolated the two battery banks should the battery voltage drop to a predetermined minimum voltage that would still allow starting of the chassis engine.. You find the BLUESEA ACR used in many marine applications. I have a twin engine boat that has three battery banks, one for each engine and one for the cabin and there are all connected with ACR's. This design has served me well and I have never had any issued with system. Is anyone aware of a similar design used in motorhomes. Thanks, Jim Share this post Link to post Share on other sites
huffypuff Report post Posted December 29, 2015 That same boost relay is supposed to also energized when the engine is running to keep the house batteries charge. If the relay is weak it won't energized because of the vibration. To check if I'm right check for power to the small positive terminal at that relay and if you got power there you found the problem. I had to replace the relay on my coach to a new upgraded one that look very much like the old one. Share this post Link to post Share on other sites
kaypsmith Report post Posted December 29, 2015 In over 30 years have not seen a commercially built motorhome without a battery isolator, either relay operated, or diode based. As Ray said, look for a faulty relay, or if diode based, it will be a rectangular device with fins on it, with 3 heavy gauge wires attached. Share this post Link to post Share on other sites
tbutler Report post Posted December 29, 2015 Our 2004 Windsor has the capability to charge the house batteries from the alternator. I'd be surprised if the Endeavor didn't have the same feature. We have a 160A alternator. If your alternator will support the additional load to keep the house batteries charged your solution should work fine. Share this post Link to post Share on other sites