Hello,i know this a chevy forum but gmc has the same body and engine,is there someone out there that had the same problem as a friend of mine he has a 99 gmc half ton x-cab pickup,he recently changed his signal switch-cruise control because it had broke off.When he was done he went to turn the key nothing would happen,and the security light started to flash is there any way he could reset the computer thank you.

 

it should all be in the manual. i know that it shuts off the fuel pump. its a farly simple thing to reset it but eveary car is a little dif.