This 2008 GMC Sierra Denali came in with multiple electrical complaints. The blower did not work. The left side stoplight, all left side turn signals, the right side mirror turn indicator. All of the power windows except for the right rear window did not work. There were a multitude of codes scattered through various modules. … Continue reading “2008 GMC Sierra Denali, Multiple Electrical Problems”
This 2005 GMC Sierra came in with the complaint that when the vehicle is started cold, the headlights, dash lights and dome light will flicker or pulsate. As the system runs the problem diminishes but never goes fully away. This is a common complaint on many Cadillac, Chevrolet and GMC full sized trucks and suv’s. … Continue reading “2005 GMC Sierra, Lights Flicker or Pulsate”
This 2005 GMC Sierra came in with a poor run condition and multiple misfire codes stored. Code P0304 was one of the misfire codes stored. While looking at data I noted that misfires on cylinder #4 were markedly higher that most of the other cylinders. Normally when confronted with high misfire counts on this engine … Continue reading “2005 GMC Sierra, Multiple Misfires”
This 2005 GMC Sierra came in with the complaint that the speedometer does not work. In fact it was stuck at 55 mph when it was sitting in the shop key on engine off. This repair can apply to any one of up to seven gauges on 2003 through 2007 Classic series Cadillac, Chevrolet and … Continue reading “2005 GMC Sierra, Speedometer Sticks, Replacing Faulty Gauge Stepper Motors”
This 2005 GMC Sierra came in with the complaint that the air will only flow from the defroster vents, regardless of where it is commanded to. This Sierra has auto a/c controls and no floor mounted center console. Of course the customer brought the truck in, knowing that I had to lay under the driver’s … Continue reading “2005 GMC Sierra, Air Blows Only From Defroster Vents”
This 2002 GMC Sierra came in with the complaint that the blower would work sometimes, but now, it would not work at all. This truck has manual HVAC controls so it uses a blower resistor assembly. I do not recommend disconnecting the battery while this work is being done. Instead make sure the ignition remains … Continue reading “2002 GMC Sierra Blower Works Sometimes”
This 2002 GMC Sierra came in with charging system complaints that I showed the repair for in an earlier post. Now I want to show how the whole situation could have been avoided if the installer had followed simple instructions. To see that repair please click here. If you recall the owner had installed electric … Continue reading “2002 GMC Sierra, Installing a Fused Battery Lead”
This 2002 GMC Sierra came in with the complaint that the battery had gone dead and that the voltmeter was reading low voltage at times. I opened the hood and the problem was quite evident to me but I decided to do some testing anyways. The following picture shows 14.32 volts at the alternator output … Continue reading “2002 GMC Sierra, Erratic Charging Condition, Battery Goes Dead”
This 2006 GMC Sierra came in with multiple problems related to being struck by lightning. It was only during the process of repairing other systems that I noticed that the glass in the driver’s side mirror was etched with actual lightning bolts. I personally think it is kind of cool to have a physical recording … Continue reading “2006 GMC Sierra, Changing the Driver’s Outside Mirror”