Yukon XL Start Issues

[bucrepus]

I apologize if this is the wrong forum but I didn't see a forum for my year model. I need some experienced help if possible. I have a 2009 Yukon XL 6.0L, low millage.. No codes have been thrown.  Battery and alternator are good. The key is a normal key I think, no RFID stuff. As normal, when you stick the key in the switch it chimes and the display and gauges come on when the switch is turned.. then it cranks. I have a progressing issue where I insert and turn the key that nothing happens...no chime, no gauges light up, no crank. almost like it has no battery... After several turns of the key everything comes to life and it cranks fine. Here are a few more symptoms. I have seen the touch screen radio display flicker while driving... Another time I turned to crank, the starter engaged, and it instantly died a second later like you pulled a plug. Also normally, when the switch is cut off the radio plays a little longer until the door is opened, the interior lights come on, and the headlights stay on for a few minutes. When I parked last night and cut the switch off, the radio just died, the headlights cut off, and the interior lights did not cut on when I opened the door. I even pressed on the remote unlock / lock keys, rear access open.. nothing. It was like the battery was unplugged. I got back in, put the key in the switch and nothing.. About 2 minutes later I tried again and it cranked up as if nothing happened. The remote control worked as well as everything else. I thought it may be the switch, but when I switch the vehicle off the interior lights wont work, the remote quit, inside lock buttons quit..etc... Kinda ruled the switch out maybe?

Any ideas would be greatly appreciated. I don't want to start buying random parts to try and fix..

Thank you for your time..

 

[sefiroxx]

The key cylinder fits inside an aluminum housing. The housing holds a button switch that is engaged when the cylinder is turned. It's mechanical and can get stuck. May have to remove the cylinder (plenty of videos), try spraying the button with wd, and manually engage the switch a few times.

[bucrepus]

Would that button switch stop the electronics (headlights, interior lights, locks) from functioning as well when it is stuck?

[sefiroxx]

It controls the bcm which times the early on late off. Also sends a signal to the bcm as to whether the driver is starting the car , so enable lights, radio etc

[bucrepus]

Thanks so much for the info...I will look into it..

[intheburbs]

I'd bet money you have a loose battery cable.

[swathdiver]

Yep, bad/loose cables or a bad cell in the battery.  Is it two or more years old?  A bad cell can play havoc with the electrical system.  As can loose/corroded cables and grounds.