What is it that usually goes wrong

[Skunksmash]

What is it that usually goes wrong with the power lock system in these old trucks? This is the first one that i have had with the power locks option but they do not work, on either side. The button feels... strange to me. It does not feel like any power door lock button that i am used to. It does not make any kind of clicking noise when you flick it up and down, which leads me to believe that maybe the button itself is the cause of the trouble. Just wondering if maybe someone knew of a common problem that might be there. Before i go replacing both of the actuator motors.

[Dragon]

They're supposed to be smooth and quiet with their movement....  GM basically decided to start supplying all of the Brand Lines with the switches that they used in Cadillacs over the years, and the only noises were meant to come from the rods movement(The Actuators were also meant to have some what silent movement, so long as they were working properly)...

Generally you can hear a slight noise from the actuator moving the rods, but if no noise is present at all, I would start with the fuse, then check the contacts for the back of the switch itself, and check the actuator connection....  Usually I find that the Contacts, and Circuits on the back of the switches need to be given a good cleaning(I use a small wire tooth brush, or 80grit for the Circuits), then covered with a Dielectric Grease for protection from any new corrosion....  Sometimes, I may find that I need to completely disassemble the switch from the chrome bezel, and give the pieces a thorough cleaning with Alcohol, and reassemble with a light coating of white lithium grease to ensure smooth operation.....  If all checks out, and it still isn't functioning, then I would suggest "CAREFULLY" checking the actuator with a separate direct power source(An Old Flashlight/Lantern Battery will work great, if one is easily available)....

NOTE: It is my experience that if neither of the doors work, it can be either side that is causing the problem,so it would be a good idea to check both.....  Every GM Car/Truck that I have played with that had Power Locks, if one side was disconnected/had a crap connection/burnt switch/actuator, then both sides wouldn't function....  Basically Both sides made a complete circuit, and any problem, would disable the entire system till that problem was fixed....

[JJSZABO]

Don't forget the relay.  There is a relay in the system that may have gone bad.  If it is a stock setup, the relay is bolted to the steering column underneith the dash.

[Skunksmash]

Cool thanx for the replies i will start by taking a look at that stuff.

[78 Chevyrado]

I used to have problems with the socket that plugs into the back of the switch.  I had a switch go bad and when i took the plug off it loosened and the new switch wouldn't work either.  The switch has studs on the back that are the contacts and the connector has a bunch of barrel shaped plugs that go on the studs.  I had to crimp the barrels down a bit so they contacted the studs properly.

[VileZambonie]

Any electrical problem you go right to the source of the problem first. If you have a light go out in your house, do you go to the fuse panel first or check the light bulb? why would a car be any different?

All of your controls run through the master switch which run through the drivers door. The first thing I would check is for broken wires in the door jam harness and then check the circuit at the drivers door.

[Skunksmash]

Ok. Finally i got the truck back from having the transmission rebuilt and i am so happy to have it back. Anyway i went to autozone and got one of those new switches for the power door locks. It is a HELP! brand product. At least thats what it says on the package. So the old switch was defective, but with the new one all hooked up i only get the passenger side to jiggle and make the lock/unlock sound. It does not actually lock or unlock it just wiggles a little and does nothing. The driver's side still does nothing. Before the new switch, both sides did nothing. Any thoughts on what this could be? Probly just need to replace both actuators, huh.

[ccz145a]

You can try to activate them by applying voltage directly. Make sure all the rods are in place and move freely.  Check the wire condition. Try to isolate each thing you need to test and you'll spend less and fix the problem faster.

[VileZambonie]

Disconnect the actuator electrical connector. Put a test light in place of the actuator and move the switch up and down. If it lights up in each direction the actuator is bad. If not it is a wiring issue.

[Skunksmash]

Now the passenger side works, after spraying some WD-40 down the hole for the little lock handle. Didn't work for the drivers side. Oh well, a new one is all of 20 bucks, and if that ain't it i just take it back to oriellys.

[Skunksmash]

Oh yeah, one other thing. Are these locks sort of... reversed in some way? As i said i bought a brand new chrome power door lock switch. Now, only the passenger side works, but if you flick the switch up (towards the roof of the cab) it locks the door. If you flick the switch down, it unlocks the door. Is it supposed to be this way? The switch is not upside down. I can read the word "Lock" right side up on the switch.

[VileZambonie]

Disconnect the actuator electrical connector. Put a test light in place of the actuator and move the switch up and down. If it lights up in each direction the actuator is bad. If not it is a wiring issue.

Do this and report your results

[69byrd]

I was wondering if you ever got this fixed and if you did what did you do.  I am having a similar problem when I hook up the power to the locks the passenger side will lock and then it will click and wiggle around without touching the switch.  The driver side will click and wiggle but it will not lock.  If anybody has any ideas please let me know.

[oldredtruck]

there is also a little stamped steel lever at the lock mechanism which has a half moon-ish shape cut out to it with a "keyway" also...both mine wore out ( obviously drivers side first) - if it isn't electrical maybe this little buck fifty part is the culprit?
just being the devil's advocate as usual...

[69byrd]

I did what Vile said and when I put the light on it, it was hot all the time.  Nothing was braking the current it didn't matter if you moved the switch up and down it just stayed hot.  It is like the locks keep locking and unlocking over and over.  Do yall think it could be the switches or could it be the relay?