hey just dropping in to see if i can get some help on a buddys 1999 yukon 1500.
hes got a problem were the speedo and clock wont work at all. so he started diging around looking for an answer and when he got to the ECU he found a few problems on a 24 slot plug on the computer. There is one green/white wire that has been pulled out.. pin and all. and another white wire that has been cut and no other end in sight. does anyone know what these wire are suppose to be run to? i believe there are white,black, red and blue plugs. the one im refering to is the black one. any help would be appreciated

 

If I find a diagram I'll post it but for the one where the pin cam out you should see where it goes.
Each pin hole that is NOT used has a little bubble over the hole that seals it so water can't go in. The hole without that bubble would likely be where the pin came from.

 

alright thank you. i do have two different haynes manuals for the truck but neither of them have the wiring diagram for this plug.. ill try and find which slot that one wire goes to how you said.