I had the weirdest thing happen to me in my 1988 Prevost. When I went to take off, put the transmission (Allison 5 speed) in gear and pressed on the peddle, I got nothing... the engine didn't even rev up. Needless to say I didn't get very far. If I put the transmission back into neutral and press on the peddle it will rev up normally. But in gear, I get nothing. I know that the transmission is shifting (I can feel it) but no check lights. Nothing. Any ideas would be helpful. Thanks in advance.