Originally Posted by rjrvtravel
Question - I have a 2007 Four Winds 23A Class C RV. Having lots of problems with the electrical system. Our 2 month old battery went dead after sitting 30 days in the yard after a 17 day trip. I recharge it and put a battery tender on the chassis battery. But I was told to remove the battery tender - and test the battery each day for a week. After the week - it had discharged .48 volts. I asked our dealer for a electrical layout - then I could determine what is draining this chassis battery. I also reay our owner book and they talk about a battery isolator controller and a battery isolator? I asked my dealer - what if this battry isolator is bad - could the chassis battery get drained - she said maybe - but she thought the computer on the engine was draining the battery? How is this possible - 30days and a dead battery? Ron
Assume we are talking about the chassis battery and not the house batteries. Are the house batteries going dead too. Turn off the house system and remove it from the chassis system to isolate the house. If the chassis battery is ok after several days then the house Is drawing the chassis battery down. If the chassis battery goes dead after house disconnect then the chassis as a parasitic draw. Thirty days with out use maybe asking a lot form some chassis systems depending on condition age etc.
The chassis dealer should be able to do these tests if your not able............
To troubleshoot the chassis:
The parasitic draw is the question (key off amp draw). This done with a DC ammeter preferably a clamp on type or inline ammeter capable of measuring milliamperes. The normal parasitic draw would be about 10 to 50 ma. 10 to 50 ma is the clock, commuter radio memory etc and is the normal draw. A draw of 250 ma would run the battery down in about a week or so depending on the state of charge, capacity of battery etc. Note 10 ma is .010 amps or another example 250 ma is .250 amps or 1/4 amp.
The draw test must done with key off, RV sitting of several minutes so the chassis systems go to sleep this is really important on a newer chassis that might have a CAN bus wiring system. This is also true about radio systems with blue tooth and navi systems that may say active after key off.
That brings us to the usual causes...........add on equipment ( alarms, radios amps etc), map light, storage area lights, glove box lights etc, power door locks sticking on
If you find excessive draw removing the fuses one a time until the parasitic draw drops to acceptable level is the normal procedure, this identifies the circuit then the items on the circuit must be checked.
This is not rocket science but it does take some skills to get it done correctly.