I have a 2004 GMC Yukon with 105,000 miles. 3 months ago the lights on the air conditioning began to turn on and off from left to right side ocntrols, then the gas guage began showing no fuel at times then going back to normal, and most recently the speedometer shows either reduced speed or drops to 0, then goes back to normal. Is there anything i can do to fix these issuues?
Sounds like you have a bad ground or power to one of the modules on your Class2 data line. Check all grounds with a test light, and power with a test light. If that doesn’t fix it i would check the splice pac under the dash on the drivers side. Any one malfunctioning module can cause this erratic behavior.