Turkey Trip Thwarted

This one has me scratchin my head. We are on a 1990 Class a Motorhome built on a Ford Econoline chassis, with 20k miles on the road. A bit weather worn though in good shape mechanically.

Prepping for a Turkey day camp-out. All preflight checks complete and clean. Let’s put temp in the motor. NOTHING. Not a crank, not a click nothing.

Dash gage reads 12 volts. There are new batteries (2), though I add a 50 amp charger, jump (from running truck) nothing. All connections clean connection to starter clean.

The trip is now aborted the family outing is thwarted.

Seven hours later, key to the ignition and it lights right up.

WHAT ? ? ? ? ?

Any thoughts out there? Might be able to still make the trip though . . . I don’t know.

At a guess, either the ignition switch is failing or some interlock that prevents the engine from starting in gear or without depressing the brake or something along that line needs adjusting.

Problem is that you won’t be able to turn the ignition off with real confidence that it will start again until you pin the problem down and fix it.

Maybe someone else has a clever idea that can get you going with some confidence that you won’t need a tow home. I don’t. Sorry.

Good heads-up, thought of the being “in-gear”, and checked, there is no brake depression requirement, that’s what it feels like. Perhaps a failing switch is it.


Find the engine to body ground wire. If you can’t find one, install one. Change the negative battery cable. If it connects to the fender before it goes to the engine, clean that spot. This is the test for a bad negative cable–Using jumper cables, connect both clamps to metal on the engine and both to the negative terminal and try it. Corrosion is the enemy of old vehicles.

It’s more than likely one of the following:
Ignition switch.
Neutral safety switch.
Starter solenoid.

All of this is easy to inspect and replace if necessary although I’m not a huge fan of replacing parts en masse.
The best place to start is the solenoid by using a test light or Voltmeter to verify that voltage is being provided to the solenoid when the key is turned to the START position.
If voltage is present, bad solenoid. No voltage present means a faulty neutral or ignition switch.

Another less likely possibility could be a fusible link power supply with a corroded or burnt wire end. (provides power to the switch, etc.)