We have a 99 gmc savana. The power door locks just keep acting like they want to lock and unlock. When you push on the drivers side lock switch it won't open any of the other locks and when you push on the passenger side ones it will occasionally open the drivers side but there is resistance. We have taken it to a mechanic and taken out our security system which has made no difference. the mechanic says one of the locks is getting to positives and can't figure out why when he has gone over the wiring scimatics. to add to this for some reason when the locks are spasiming it blows the stereo and its on a different fuse. nobody seems to be able to help us with this and we can't reinstall a security system until we get to the bottom of this which is frustrating when we have valuables inside. they have tried each of the locks individually and they are all working properly on their own.
power door locks that spasm on 1999 GMC Savana 2500
I just had a similar problem I had to take all the door panels off and remove the electrical connections at each lock solinoid which are each mounted right on top of the door lock mechanisms themselves. Takes a bit to remove the lock/electrics, they are cheaply made. The dealer was expensive but got parts aftermarket from I think Dorman from our local parts house.