This just started this year a couple months ago when it started getting cooler. one morning went out and got into my car and started it and noticed that light up for the PRNDL to know which one I was in was not showing up, and my gas gauge showed empty when know I had full tank, then tried to turn defroster on and turned fan on high and nothing, so I figured when gear I had it in started down the road and noticed that the doors did not automatically lock after you drive just a few feet, and so kept on driving and about 5 min later noticed panel went to work and fan started working, then did it again but only when it was cool at night and first go out and start after sitting in the cold. then about 3 weeks ago because friend couldn't figure it out who is a GM retired mechanic, he setup appointment to drop off at local GM dealership here and as I got in the car from church that night to take by and drop off, it was doing it no heat and it was 49 degrees out, had to figure out what position it was in so I could drive it, gas gauge sitting on empty, temp gauge stayed down at 160 and my seat belt would come on and then stay on then go off then come back on, and my bright light indicator wasn't working and I was a good 20 min to 30 min from dealership and none of the stuff worked until I got to the dealership and the best guy at the dealership has been trying to figure it out for 3 weeks, they say it does it but not long enough for them to get a good reading on what the problem is. Can anyone please tell us what this is, like I said I've owned it for 4 years now and it just started doing this so I've been without my vehicle for 3 weeks and my husband and me are having to share a vehicle and it is hard for me climbing in and out of his big truck. I really miss my Yukon and want to get it fixed right and get it back. Please if you know what this maybe please let me know so I can tell the mechanics. Because we know it can't be bad cluster since it's effecting my ac/heater fan blower not working and then all of a sudden when cluster panel goes to working for a few minutes the blower goes to working and the automatic door lock goes to working. we've wondered if it's something to do with ignition switch? any help would be so greatly appreciated.