Motorhome won’t start

D.E.Bishop wrote:

MEXICOWANDERER wrote:
Just perform a full diagnostic as you would with a station wagon or SUV.

Keep in mind things do wear out. Not every electrical failure follows a series of tattletale intermittent malfunctions. Some things may just quit.

If a solenoid "clicks" it is one clue. If it loudly CLACKS it's another. Turn on the headlights. Someone needs to see them and report. Try to start the engine. Do the headlights go out?

X2

Start at the beginning. On my rig the Battery Mode Solenoid was clicking when the ignition was turned on but it was not making good contact internally. There was current flow but the contacts were not making firmly, there were carbon traces and pits in the contacts and slop in the movers travel, which kept it from making full contact and allowing full cranking amperage to flow.

A simple test, maybe not conclusive but easy to do, it too will take two people to perform. One person turns the ignition on while the second person is at the solenoid and after the solenoid is engaged and the engine does not crank, jumpers the contacts. If the starter motor cranks, it would seem logical that the contacts of the solenoid are not making good contact and, therefore, not allowing full cranking power to pass.

Had a similar "hidden inside the clamp" corrosion issue at one of the coach batteries in my Roadtrek about 8 years ago. Noticed it felt a bit loose when checking connections at the batteries. Pulled the clamp off, pretty much fell off, stripped the insulation back past the corroded section and cleaned it up. Replaced the clamp connector. Success. Symptoms were low battery SoC status and genset wouldn't turn over intermittently.