power door locks

[kglowacky]

my power door locks on my 78 Silverado has an issue. They will work locking the doors but will not unlock them using the factory button. Any ideas? Maybe the button itself. Looking for thoughts before I remove door panel.

[old Rusty C10]

most time it is the button.. if you can pop off the left side first, try using a power probe to send power and see what they do 99% of the time its a button or connection to button issue

[kglowacky]

will do. will update

[rodstored-72]

keep us posted, I am having a similar issue, but I am pretty sure it is a button/switch issue for me ???

[Chevrolado]

I just removed my door panel the other day and noticed the connection points get pretty crusty/dirty. I'd suggest pulling your panel, pull the plug off, clean up the contacts and stuff and plug it back in. If the power is working to lock them, chances are high the wiring is fine. It's likely just the button trying to contact the unlock side is gunked up or no longer making the connection properly.
Mine seem to work when I push and hold or hit it a couple times in a row.. again leading me to think the contacts are just messy (which is why I started digging into it).

[rodstored-72]

I spent some time this past weekend and replaced the inner/outer felt runs for the doors....so.. while panel was off I spent a few minutes looking at my lock switch. I cleaned the contacts (fine pad) along with blowing out the back of the switch. I "squeezed" some electrical grease around the lever (up/down motion) and worked it in some. it appears to have fixed my issue, the lock switch now works when pressed up/down. I will eventually replace the switch(s). not sure if this might help you are not. I thing the majority of problems are related to age & "dirt". spend some time & clean the contacts (switch and harness), clean the switch housing good & apply some elec. grease around the up/down lever and just work with the housing to "replenish"/renew the switch.

good luck!!

[kglowacky]

just an update. I pulled the switch. It works to lock but not unlock. Tested for power on orange wire. Yes I got power. put power to each wire ,one at a time the locks work perfectly. Took switch over to my wire wheel cleaned off the grim hooked back up no good. I remember when I bought the truck there was a box with a new plastic switch in it, got it out wrong pin positions. Mine is a metal case with 3 corner plugs, the new one is three across. Did some searching seems no one has the metal correct one, Anyone know anyone that had a good used or new one for sale. LMC says the part number is 36-0740 (out of stock). I hate to cut up a new harness to install a new pigtail. Thoughts. Anyone have the GM Part number.

[kglowacky]

bought a original style door lock switch from my local C-10 supplier Outback Trucks in Spring Texas. Not cheap but I got one. Now the challenge it doesn't snap into my current opening, By the way the locks now work both ways, so it was the switch. Took me 10 minutes to replace after an hour of logical or not logical figuring on how it installs. Here's the trick the switch comes with a bracket that is installed on the switch. You got to remove the bracket and fasten it to your door panel first (by bending the tabs/ears) (It looks like a picture frame). The new switch then snaps into it.

[rodstored-72]

thanks for the update & the tip!! glad the issue is worked out.
nice job!