Community Forums

Bruce39 · 06-05-2017, 11:22 AM

New to me, this coach started easily on the engine battery. Battery did not seem to run down at all. Sitting in my yard plugged into shore power, the engine battery runs down! If I start the engine (on the aux. batteries), it starts and charges the engine battery! Measured the voltage at the battery, dead! Started and then measured, 14+ volts with engine running! Stop engine, battery measures lower as it has not had enough time to charge off the running engine!
Why after a month or so in the driveway, not connected to shore power, now connected to shore power is the engine battery running down? Cannot think of anything else I have done to cause this!
If someone has a REAL wiring diagram for this coach, I would be most appreciative! The “book” only has sketchy sketch’s!

imob · 06-05-2017, 11:35 AM

This one sounds simple enough... Your engine battery has dropped a cell. It happens. Replace the battery. From the sounds of it everything else is doing exactly what it should be doing. Also some rigs will not charge the engine battery with the house batteries. But oddly going the other way the engine alternator will charge the house batteries. My guess is that they have this design because the different battery types would need different charge circuits from the converter.

A battery in good working order will not drop charge in a month without something drawing it. Take the battery to your local parts store and they can test it.

Also make sure while you are in the battery compartment to take the time to clean and check all of your connections.

BFlinn181 · 06-05-2017, 11:37 AM

If your RV has a Bi-Directional Isolator Relay Delay (B.I.R.D.) it disconnects the house and chassis battery groups until a charging voltage (+13.7v) is detected. Your description shows your isolation relay isn't working in both directions. I suggest you search your electrical bay and see what you do have and then use Google to search for that unit and then folks on here can help you test it and suggest solutions.

Intellitec makes many types of modules, perhaps you have one.