I have a 98 yukon 5.7l. I replaced the dash in it yesterday. Now it will turn over but will not stay running. I am 99.9 % positive that I plugged all my wires back in except I did miss the passenger side airbag but will do tomorrow. Also did not do the driver airbag to make sure everything was OK but hince I did have a problem. If I may have missed a wire, what could be causing it not to run? What else could it be?

Don't know gm... but if it was a ford...
Did you replace the cluster or just dashpad and transfer all parts to new dash?
The antitheft module is in the cluster? And may have to be reset to read the pats key chip. Or by disconnecting it may have to be reset to read the pats chip. "98" should have pats? Like I said ford certified tech not GM

No I didn't replace the cluster. But I didn't mention that the wire (3 pin) going into the top of the key cylinder was unplugged while taking some components loose to get clearance on the steering column. It is plugged back in though. I was told about a security cable or something on the column but everything is plugged in. Help!!

OK there is no security light coming on at all. This light is needed for it to run. Any suggestions?