Been having an on-going problem with shift pad activation on my Allison MD3060 tranny. When ignition is turned on or engine is started, shift pad does not activate or light up. In the left front MH electrical compartment I have identified 3 relays that service the tranny. If I jump with 12v. on the center relay to trip it with engine running.. then pad is activated. Once turned off problem is back when engine is restarted. All 3 relays bench test OK. Allison people said to check 24 pin connector at tranny for corrosion or shorting (did this to find no problems). They mentioned something about pad not receiving a "wake up call"??? Should shift pad activate when ignition is turned on or does engine have to be running? I would like to troubleshoot this myself so any help would be great.

My trans pad activates immediately on key going to the run position before the engine is started.

Have you done the diagnostic check of the controller? You can do this by holding down the up and down shift arrows during ignition turn on. I suppose if it isn't lighting on turn on, that probably won't work, just a thought. I have a list of the codes in case anyone is interested.

I have a procedure to wait until I have the trans pad lit before I crank. If I turn the key immediately to start from off, the engine will not fire right away because the fuel solenoid takes awhile to activate if the engine is cranking.

FWIW, the PO replaced either the pad or the controller for some issue a few months before I bought it, but I have had no problems so far.

HTH

Finally solved the problem..traced all wiring in electrical compartment and located all the relays that deal with interfacing between mh wiring and trans. There are six relays (3 out in the open and 3 that were partially hidden) One of these relays was defective and did not send the 12v needed to power up the shift console...all is working as it should, with shift console lighting up when ignition is turned on. thanks for the help.