97 yukon, check engine light

Alright guys, I've done probably a hundred of these things, as im sure many of you have done your fair share. 1997 GMC Yukon. I put in an AstroStart 4204. Very basic vehicle. I hooked up 2nd Ignition like I always do, and and powered up the programmable relay BEFORE starting the truck, as from previous experience, that will trigger a check engine light if not done in that order. Well, install went fine as always, tested it out: all is well. Customer calls today stating his CEL is on now. He JUST bought truck, had it for like 2 hours before I put the starter in. I will check the code, but I just dont see how my install could be causing this. I will be checking over the install tomorrow sometime, I scheduled him in for an appt. AstroFlex did mention a third ignition wire pink/white that only some of these trucks have. I dont remember seeing one, or have I ever. Any ideas guys? Thanks again. Shaun, we are the same height, that is neat!

12V Installation Technician for Honda, Dodge, Chrysler, Toyota and Jeep.

Some have a third ign. pink/white......you got one? Try that?

I didn't read your post real closely....sorry. I will bet on the 3rd ign. being the problem.

well, i will surely check that first when it comes back in tomorrow. Im ALMOST positive it didn't have a 3rd ignition, but I will see. If its not that, and all else is fine...Im at a loss for what it could be. I guess i will check the code and look it up, maybe its just pure coincedence and its a vehicle problem, but I wont assume that right away. Shaun, we are the same height, that is neat!

12V Installation Technician for Honda, Dodge, Chrysler, Toyota and Jeep.