I just recently purchased a 1985 prevost-patty


Patty, If you just got the bus there are somethings you want to look at. I would find out about the life of the chassis and house batteries. It they check out using a battery tester (load tester) then you can start looking else where.

we're having to run our coach motor to charge batteries-patty

Why is there a need to run the Detroit?

Sounds like you should break down what is going on...I mean the gen-set should be running to charge the house if the inverter isn't working. Sounds like your plugged in.

The Detroit charges the chassis batteries, but how do you know they need charged it the engine starts.