Have you become so frustrated with your non-working power door locks you’ve decided to take drastic measures to pull open the locks. Well, Bunkie, put away those channel locks. The solution is right at hand. The most common problem with 78 to 82 Corvette Power Door Locks are broken pigtail switches. It seems with age and use, the pigtails break leaving the power door locks inoperable. Replacing the pigtails is fairly simple. Start by making a call to Zip Corvette Parts, 8067 Fast Lane , Mechanicsville, VA 23111(800) 962-9632. They have the new pigtails readily available and in stock. The repair will only take a few hours and if the door actuators are still good, the expense is very minimal. You will only need common hand tools for the repair but I would recommend that you have a wiring diagram and shop manual available for your year Corvette.
Now let’s get to work and put the switch on. 1978-1982 Corvette Power Door Lock Repair:
01: Here are the new Corvette door lock Switch Pigtails we received from Zip Corvette Parts. If you look closely you will see that they are marked for the left and right. The reason for this is that each mounts differently to the switch and each side has different colored wires.
02: Start by removing your Corvette’s door lock knob, armrest, door handle bezel and door panel mounting screws.
03: Carefully lift the door panel off the door. Support the panel while disconnecting the pigtail from the switch.
04: Here is our problem. The pigtail has come apart. The fiberboard back should be attached to the pigtail and one wire has broken loose from the mounting plate. Check the back of each power door lock switch. Look for loose connecting studs or a broken switch housing. Make sure the switch has tension in both directions when you move it. Clean the terminals of any corrosion. If you need another switch, contact Zip Corvette Parts. They will be able to supply one.
05: Just to be sure this is the only problem, you will want to check the door actuators. Start by removing the access panel.
06: Remove the electrical plug to the door actuator. Make up two long wires with alligator clips on both ends. Connect one wire to a good ground and then to one spade on the door actuator. Use your second wire and clip one end of the wire to a 12 volt power source and the other end to a probe. Touch the 12 volt probe end to the open spade terminal on the door actuator. If the actuator is good, it should work in one direction. Reverse the wires on the actuator changing the ground to the other terminal and the 12 volt source to the open spade terminal. The actuator should work in the opposite direction. Try this 2 or 3 times. If it works in both directions, the actuators are good. If it doesn’t work, the actuators will need to be replaced. Contact Zip Products. They will be able to supply you with new ones. Note: Make sure you have a good ground and 12 volt power source. If you do not, the test on the actuator will not be accurate. Remember that if your actuator does not work the first time you try this test, it does not necessarily mean that the actuator is bad. It may mean that the actuator is already in one direction either locked or unlocked. By changing the wires around on the actuator and trying the test, you will be making the actuator work in the opposite direction.
07: Verify the wiring from the door harness to the pigtail. This is very important. We noticed that some of the years vary in wiring color. If the wiring is not connected correctly, the door locks will work in reverse or not at all. (This is where the wiring diagram for your year Corvette is very important.) You can use butt connectors to crimp the wires together but a better way is to solder them. If you solder the wires, you will be able to do most of the wires on the passenger door out of the car. This is much easier, but the driver’s door will have to be done on the car.
08: Use heat shrink tubing to cover any soldered connections. This looks much better and is more waterproof.
09: After the connections are made, plug in the door lock switches and try the door locks. If you did everything right, they should work perfectly. If not, you may have crossed a wire or the switch is defective. Use either vinyl or electrical tape to make a new harness cover.
10: Re-install the access plate and feed the new pigtail up into the door and out the upper access hole.
11: Align the door panel onto the door and connect the pigtail onto the switch. Re-install the mounting screws, door handle bezel, armrest and door lock knob. You are done and ready to flip that switch. No more channel locks for you.
12: These are two Corvette Manuals you should not be without whenever you are doing any repair to your Corvette.
The Switch is On: 1978-1982 Corvette Power Door Lock Switch Repair
Text and images by Greg Donahue.
Zip Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632
Corvette Parts List Related to Article:
- 1978-1982 Power Door Lock Switch Pigtail
- 1978-1984 Power Door Lock Actuator (Delco)
- 1978-1982 Power Door Lock Switch
- Shop/Repair Manuals