Driver Seat is dead.....

citydriver · November 30, 2019

Just something you guys can check that I've run into a couple of times. If the fuse is good and the contacts in the fuse panel/block are clean (corrosion is an issue at times in the under hood fuse block, especially in areas where road salt is used in the winter). Check the main wire harness connector under the seat. Check for power AND ground connections on both sides of the connector (sorry, I don't have pictures). I have found problems with the main ground losing connection due to corrosion. If it's corroded, that damn connector is a royal pain to get apart. If it was loose and caused arcing, the connector body may also be melted. But it's usually that main power connecter under the seat that causes the issues if only one seat is not functioning.

06pirate · November 30, 2019

Two weeks ago I had the same problem, drivers seat dead for motion and heat. Found the connector underneath loose and backed out about halfway and also slightly corroded pins/sockets. Scraped and blew out the crud and reseated the connector and all works good.....for now. Note that I use the heater every time I get into the truck, and recline/upright the seat every day when I eat my lunch/nap in the truck.

Hollandgmc · December 7, 2019

I have an 05 Sierra 1500 SLE. I purchased the truck at 170k miles. Seat heaters and power seats worked great for the first few months I had it. Now I have no seat heaters working in either driver or passenger side seats. Driver seat is also dead and doesn't move but passenger seat has power yet. I also checked my fuses and looked for loose wires and all seem to be good. Reading these gives me more things to try before i take it in for professional servicing.

mgdlp8815 · January 27, 2020

Hey guys, was having a similar issue. Drivers side specifically heater and now power seat. went to black connector beneath drivers seat in the back side. Disconnected then reconnected and works great now. Was able to at least pinpoint the specific trouble area. Heres a link i found on youtube exact location and connector.

Buggy118 · April 22, 2021

I have a 2004 GMC 2500 HD I am having the same problem- what fixed yours?

Figured_It_Out · September 16, 2021

The driver's seat was dead in my 2005 Avalanche similar to what I'm hearing from others here. The cause was a connector pin that had been damaged from too much current. I think it's probably the heating element in the seat which I use frequently in the winter. The driver's seat goes out first because that one gets used much more than the passenger seat in my case.

For those that have a maintenance manual it was the power supply pin in connector C305. This connector is located under the driver's seat toward the rear. Mine was mounted to the floor. You can see that the pin got hot enough that it melted the plastic on both sides of the connector.

Replacing that connector looked very involved. I did reseat the connector and the driver's seat came alive again but I didn't trust it. It's likely it would have eventually failed again so I opted to just cut the power wire on each side of the connector and crimp in a new section of 14 gauge stranded wire.

Rick Raldiris · January 23, 2025

I recently discovered the problem for my mystery loss of functions on my 2004 Silverado SS, which made no sense. I too had a driver’ power seat that suddenly did not work with all fuses, relays & connections good. Later my mechanic could not power up the windows after disconnecting the battery to replace a power steering pump. My problem came from a Python alarm system with a battery back up. Originally, I had a Code Alarm installed in 2004. This CA alarm had a feature for a back up battery in case the thief drilled thru the fender to kill the battery. The CA had a separate input for the back up battery, which isolated it from my main battery. By 18 years later, the CA alarm & replacement Audiovox alarms no longer worked & were obsolete. My latest installer simply connected the “back up” battery in parallel with my truck’s battery, which was NOT a separate input circuit. So whenever, I replace a battery or disconnect the battery to replace components (like remove air bag to replace a steering wheel), this back up battery maintained a voltage for a long time. I just happened to discover this, as I had a cigarette lighter volt meter inserted. 1/2 hour AFTER I disconnected the battery, I saw 8V on the read out. The bottom line is this present, but degraded voltage is causing the truck’s PCM computer to loose its mind. I am certain of this, as this occurred 3 times to me, losing different functions (lost all gauges, or lost interior lights, etc; but truck would start with headlights functioning). I need to get alarm guy to either remove this BA battery or install a relay to isolate this BA battery UNLESS the truck is running OR alarm is triggered. This also explains why my Optima Yellow top battery kept discharging when the truck sat parked for 6or more days. I measured 4/10ths Amp before having my LoJack ripped out, but I still read 1/10th Amp drain using my Fluke DVM with DC Hall effect clamp on transducer. These residual voltages REALLY confuse the vehicle computers on this age.