While installing power windows in my '77, I thought that I would try to get the existing power locks to work. Everything seems to check out - the solenoids work when power is directly applied and the switches and the wiring all have continuity, but when everything is hooked up nothing happens. :( I've looked at countless diagrams, but everything seems to be different from what I have. I only have 3 wires - orange, green, & black - and the switches only have 3 pins. I don't understand where the ground comes from when the switch is used. I feel like I'm probably missing some wiring or relay...?????:roadkill:

There is a reversing relay somewhere around the lower steering column or near the kick panel. Normally with GM, orange is a power feed to the switch, black and Lt. Blue control the relay. Tan and gray power the solenoids. This is for later years though. What year do you have?

Do you hear the lock actuators clicking??
My 78Z is doing the same thing, but I can hear them clicking.

The locking mechinism on the door is really gunked up and the actuators do not have enough umph to move it.

I have an extra lock mechinism that I cleand up and lubed. I will replace that and see if it works then.

My car is a '77. No clicking at all & the mechanism moves very freely. The more I study the system, I must be missing the reversing relay. I looked all around under the dash & don't see one there. Anybody have a part number or know where to get one? Will one off of another '70's GM car/truck work?

http://image38.webshots.com/39/4/30/11/315643011WMnACH_ph.jpg

This is the wiring that should be in your car.
You might have the wrong stuff in your car.

as you can see from the wiring diagrams, there is no relay in this system.
I am posting pics from my car (the interior as apart, so I can get the pics easy.)

Both switches should have 5 pins, you are reversing the polarity of the actuators by using the switchs.

Also, I believe that BOTH switches have to be there for the system to work.

http://i23.photobucket.com/albums/b355/spoonlt1355/lock3.jpg
http://i23.photobucket.com/albums/b355/spoonlt1355/lock2.jpg
http://i23.photobucket.com/albums/b355/spoonlt1355/lock1.jpg

Anyone know where to get the terminal ends for these wires...the little clips that the pins push into. Mine are corroded. I don't want to replace all the wiring cause it's in good shape other than the terminal ends.
Since this is a weak spot that causes the PL to fail... others might benefit.

Thanks so much fo the pics!!

Hmmmm, my switches and fittings that plug into them only use 3 pins. The wiring diagrams I've seen seem to show what's in your pictures. I'm pretty sure that what I have is oniginal to the car. The wiring runs through the plastic channel behind the dash and, trust me, from the amount of gunk, I seriously doubt that the dash has been apart before I got to it. But in a 29 year old car, who knows? No relay in your system?

Yeah, I've fought with those terminals before too. Love to know where to get some!