My '95 U-240 CAT 3116 with Allison MD3060R will not start(engage starter) until relay R1 on relay/wiring panel in front of the passenger seat clicks on and holds. The relay R1 is labeled as Neutral Safety Switch. The relay(R1) will start to chatter after a period of time(30-90 seconds) and finally click in and hold. The engine will start then with no other problems. I know that the relay is energized by a wire(purple) coming from the Allison ECU tranny(WTEC II) controller.
First is it possible for the tranny(MR3060R) to be in gear(R/D) after the ignition has been in the off position and then returned to the on position and then start?
Second does the Allison MD3060R have a neutral safety switch in the tranny or is this just a function of the ECU?
I don't think there is a switch, I think this was for the lever operated gear selectors. I think with the touch pad gear selector the R1 relay is a left over and not needed. I think the ECU and tranny ensure the engine starts with the tranny in neutral.
Tell me what you think, am I wrong to do away with the relay(R1)?
Pat
I had a related starting problem. With the help of an especially able Foretraveler, I finally figured out that, instead of battery voltage, I had 11.7 volts at the Allison ECU on wire number 123. That meant that the NSS relay was only getting 11.7 volts. Everything else checked out. I ended up bypassing the Neutral Safety Switch. In the central 12v wiring area behind the panel in from of the passenger seat, I jumped 122 and E9. this sends 12v back to the start relay in the back. The Allison always defaults to Neutral so it's not a safety issue. I would think your setup on the 95 would be very similar to mine. Good luck.
jor
Since this relay is a common Bosch-type relay, have you first tried to swap it out? Could chatter be from Allison receiving a too low voltage from an up-stream source?
Thanks jor for the comment. I agree with you, but I will check the voltage to relay coil.