One problem related to turn signal switch has been reported for the 2004 GMC Sierra. The most recently reported issues are listed below.
I own a 2004 GMC Sierra pickup with 6,700 miles. I am experienceing a imtermintent problem with the turn signal/hazard lights. When I activate the left turn signal the hazard lights begin to flash. I have taken the truck to the dealership for repairs, after waiting two months for the problem to occur at a time I was near the dealer. They replaced the multi function switch and two days later the problem is still there. I continue to work with GMC directly and the dealership to seek resolution but am being told that unless they can see the problem happening they cannot do anything. I am very concerned that this is a definite safety issue. If I am attempting to make a left turn and the signals are not operating as they should I could end up in a collision with on coming or approaching from the rear traffic. I believe this should be addressed immediately and repaired. Please help.