Power locks malfunctioning...

I have a '99 GMC Sierra 1500, 2 wheel drive, 305 (5.0 liter), Ext. Cab pickup (old body style). I've had it since new years eve! It is a great truck, and I love driving it; very smooth ride. I do have a problem, and the dealer will fix it per my 100 day warranty, but the warranty has a $100 deductible. So, after describing the problem, maybe you could suggest either an inexpensive fix, or recommend forking out the $100 to the dealer.

The keyless entry and the rocker switches on both door panels operate the power locks. Using either method will open / close both door locks once, but after that, there seems to not be enough power to open / close again. The levers will move part way, but will not completely engage. You can hear the relay, and see the levers move, but only slightly. I can manually open / close with either the key or by manually pushing the lock lever up or down.

I've taken off the driver's side door panel and lubricated the rods and lever. I didn't take off the inner panel in order to lube the actuator, though. This made no difference.

So, I can think of two, maybe three scenarios:

1) Both actuators are worn out. Hmmmm...maybe...

2) The relay is malfunctioning, not sending enough juice to the actuators. Seems more likely...

3) Some wiring problem. Hopefully not!

Any comments / suggestions would be appreciated!

Thanks in advance,

SunDog67

Same problem , any cure yet ?

Yes, the dealership fixed the truck, but the salesman didn't know what the service tech did to resolve the issue! My guess is that they replaced the actuators.....

Relay seems most likely. If both locks are doing the same thing, the problem has to be before the signal forks off to either side of the truck. Having both actuators go at the same time on 2 different trucks sounds like too much of a coincidence to me.

i've replaced a ton of actuators on these trucks i think their made at the same place as those stupid multifunction switches.

It's The Relay!
Kevin

GMC has been using some pretty shoddy switches lately. Pretty soon they will be as bad as Chrysler.

I also am having the same problem w/ 1999 Sierra crew cab. 3 of the 4 door locks work only part way and the 4th/rear door works fine every time. Is it the relay under the dash...right above gas pedal? Sometimes all of them work once and then partially after I keep trying. I replaced the circuit breaker (no help). The relay clicks in both directions. I think it is the relay. Seems to get worse when the heater is on and truck is warm.

This thread is nearly 2 years old. Please start a new thread, and someone will help you with your problem.

Thread closed.