I have changed out the two TAMD40As with two TAMD41As, but have kept the wiring harness and instrument panels from the old engines. Took some figuring, but had a school trained Volvo wrench draw a diagram for the wiring...only change was tachs and oil pressure transmitters. Any how...they both cranked and ran well. Recently I decided to start both engines and run them for awhile. The horns/warning sounds, instruments comes to life, but when the key is pushed in and turned for start mode...everything goes dead, until the key is returned to run mode...no starting, cranking of either engine, both do the same thing...nothing. I had a similar problem once before, and found it to be the neutral position on the gear shift and gear box wasn't correct. Moved the gear shift while the key was being pushed and turned and things came on line and cranked. Not happening now. I can jump the solenoid and turn over the engine, but not the way to go, any ideas??? Thanks Bobt