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tenspeedret360's avatar
May 25, 2014

allison transmission cummins 300 neutral safety switch

Good morning all, and a very happy Memorial Day to everybody. Take a moment to think of and thank those we honor today.

And now to the business at hand, and thanks in advance for all the help I'm sure to receive...I have an '06 Monaco LaPalma, with an Allison 1000 transmission, and a 300 cummins engine. House and chassis batteries are both fully charged.
When I attempt to start the RV, the key in the accessory position, all the idiot lights and bells and whistles on the dash work. I urn the key to start the RV, and everything stops. no idiot lights, no more bells and whistles. To get the RV started, I've bypassed the starter, and it runs. My question is this....I'm attempting to troubleshoot the 'neutral safety switch', and my first question is, does my setup have a neutral safety switch? I've gotten answers both yes and no. My next question is, where is it, what would it look like, and how would I go about troubleshooting it?

Hope these questions make sense, and hopefully, one, or many of you, can give me a hand with this....Thanks again, and have a great and safe holiday.
  • With the key on and engine running are the lights on in the trans shifter?? If no then you have no power to the trans control unit.

    Not sure about the 100 series trans...BUT you should repost your question as Allison 1000 problem. That should get all the truck guys looking that use that trans, and maybe they can answer your question. Also search the Allison Trans forum on irv2.

    Good Luck :)
  • Sounds like you don't have adequate voltage to the idiot lights and related equipment. Could be a ground issue. I would connect a voltmeter to a negative frame ground and check both the ground side of the lights and positive side.

    ie Thinking that you have a partial open and with the additions load of the starter you lose the basic ignition components.

    In fact I'd start at the ignition switch itself as it could be bad.

    It might help to know just what you did/bypassed to get it started.