Couple Issues After New Motor Install

[krisevans]

After 420 000 km the motor in my 02 sierra 1500 devoloped a knock. I replaced it with a used one from a 02 avalanche. When i put it all back together i used the computer that came with the replacement motor. I had to do the turn the key on for 10 min 3 times sequence and the truck fired up and ran fine. I then noticed the speedo was out of wack, cruise no longer works and the signal lights flash at sparatic rates, depending on rpms. when the rpms go up, they flash proper, but most times flash to fast and lightly flashes the side not being used.

I replaced the computer with the original one, and that fixed the speedo problem, but i still have no cruise and the sig lights and still acting up. Could this be an issue with the computer swap. i never had to "relearn" when i put the original computer back in the truck. I tested the cruise module and it's working properly and sending out the signals when the buttons are pushed. Should I be looking somewhere else for the problem.

 

the signal lights seem like a ground issue, but i have not found any broke and have added extras to the truck.

 

any help would be very appreciated.