Engine won't turn over

[TLizzie]

 I have a 1998 HR Imperial with a Cummins 325 and Allison trans. Today it decided not to turn over. Batteries are a year old and fully charged. Connections all seam to be good. Dash lights come on when key is on. Everything seams as usual except that the the shift selector is not lit. I don't see any reference in the manual to where the Allison control unit gets power.  Thank you

[hermanmullins]

TLizzie,

Welcome to the Forum.

Sounds like you have a bad Solenoid. In your front electrical panel you should have two solenoids. Each should have two large post on them. With the key on you should have 12 volts plus on each post. If one doesn't have power than that would be your bad solenoid. To be sure, you could jump the two together and see if your engine will start. But don't run it that way for very long. Also Be sure that you get a 12 volt contentious solenoid.

Good luck,

Herman 

[manholt]

There is also a fuse between the solenoid and Allison pad.

[Lenp]

The Allison has a neutral lockout function.  If there is no power to the Allison, the engine will not turn over.  Friend with an older Tiffen coach had to have his Allison keypad rebuilt to cure his start problem.  Started intermittent and grew.

Make sure the Allison has power to it.

Lenp 

[wolfe10]

If the Allison shift pad is not illuminated unplug and properly seat the connections at the shift pad and also the two gang plugs at the Allison ECM.

Your IGNITION SOLENOID is working since the dash idiot lights work.  Another easy test for this is that the dash HVAC fan is working (normally wired to only work with the ignition on).

There are TWO fuses to the Allison ECM-- one for memory and one for when it is "working".  Check that both are hot.

 

[TLizzie]

 Thank you for the sugestions. What I've found so far is that the fuses where the power originates are good and that there is power to the latching relay when the key is in the start position. That relay doesn't switch so I am ordering one to see if that is the problem. It looks like there has been a problem with this system in the past because there are several spiced wires attached. The dash AC blower does work with the key on. Thanks again

[wildebill308]

Good at least you are making progress. I would look for a heavy duty or continuous duty relay.

Bill

[TLizzie]

 The new relay came today. Installed it and held my breathe when I turned the key on. Still no neutral indicator. Not really a surprise because I  don't have power at the post marked neutral safety on the terminal block in the compartment next to the ECU. I Have done as Wolfe suggested and took all connector apart and reseated them. I checked all fuses including the supply voltage and the two inside the box with the 6 relays, VIM, I think its called. Still no neutral light. If it has anything to do with anything I know that the gear selector is good because I have a brand new one that I plugged in with the same results. Any ideas??? Thank you

 Just a thought. What happens if you do shut off the motor while in gear? I don't believe that's the case here but I'll try anything.

[dickandlois]

TLizzie, With the year coach you have do you have a mechanical shift - instead of a touch shift? 

Rich.

Some Starter Wiring Info. from a 2001 Coach.

Hope it helps pin down your starting problem !

2001 Holiday Rambler Rear Run.pdf

2001 Holiday Rambler VIM Trans.pdf

Rear Run Box Wiring.pdf

Starter Wiring.pdf

Note added 3/26/18. The starter relay power is supplied from a relay powered by the the VIM - this relay coil power is supplied from ECM  when the ignition key is turned on. So if there is no power out on pin 7 - the fault could be in the ECM Module or there is no power due to the leveling system safety lockout circuit.