Please help!
I recently swapped in a 454 TBI from a 1992 GMC Suburban into my 86 GMC pickup. I was able to get the entire motor, wiring harness, and computer from the donor Suburban. The motor starts, but has a high idle. I was hoping to pull the trouble codes from the computer, but there is no power to the check engine light. Even when the truck key in in the ACC position, all lights come on except the check engine light. I identified the pin at the computer which is the check engine light lead and there is no voltage at this point. I have never seen the check engine light come on in the truck and it is connected properly (I was able to get my hands on a engine electrical book from the local dealership). Why would the computer not be sending power to the check engine light?
Any help would be greatly appreciated as I am at my wits end with this project!!