Diesel will not crank


New Member
I have a 1992 American Eagle Motorhome that I have owned for 12 Years. I have just started having a problem with the engine not cranking when you first turn the key to start. It will eventually crank (at least it has so far) after a wait of from 10 seconds to 3 minutes. There is a Allison Transmission VIM behind the brake pedal on the bulkhead and when you hear it start clicking the motor will crank. I have pulled the cover off of the VIM and checked all of the relays inside but it still does it no matter where you put any relay. (there are five relays total) I do know that one of the relays is for the neutral start switch so I am sure that is what is keeping it from cranking until that relay is activated. I have cleaned all connections and battery cables but it is still acting up. It would not worry me if I knew that it would always start but you get that feeling that at some point that it will never trip the relays and not start.

I have found a new VIM from Ron The Bus Guy, but I have pulled mine out and there is not much to go wrong with them. It is a circuit board with five relays and two fuses. I am wondering if the ECM for the Transmission is not what is causing the problem, not telling the VIM that the transmission that it is in neutral.

Any help would be greatly appreciated.



Senior Member
Re: Diesel will not crank

IF the ECM was bad it probably wouldn't work at all. It sound like a sluggish power relay. When you turn the key on, power should flow almost intantaniously. I would start by replacing your ignition relays.


Senior Member
Re: Diesel will not crank

I don't think the neutral start relay in the VIM should be clicking. It should click once and stop. Since you moved relays, it's not the relay. Sounds like an intermittent neutral start signal. Could be an intermittent in wiring, corroded connector terminal, possibly the selector. Some selectors are remote from the ECM, some are mounted integrally with it. It's not likely an ECM....at least I wouldn't go there first.