Project: Retrofitting Power Locks & Keyless Entry

Background:

Power locks were avaliable as optional extra cost equipment on thirdgen (1982-1992) pontiac firebirds and chevrolet camaros. A large percentage of thirdgens do not have power locks. Remote keyless entry was unavaliable as an option on thirdgens, if you want this feature, you'll have to get an aftermarket setup.

After deciding to add remote keyless entry, I first needed to install power door lock actuators before the project could begin. I had the choice between aftermarket door lock actuators and original equipment actuators. I chose the OE route.

Parts required for retrofit:

Mandatory Parts:

Door lock electrical harness: The door lock electrical harness is not installed unless the vehicle came from the factory with power locks. Can construct your own harness if you get the connectors for the actuators from a salvage yard and some 16 guage wire & solder from the local hardware store.

Flexible wiring conduit: If your doors do not currently have power windows or electric power mirrors, it is unlikely that you will have the rubber boot installed the connects door to the body of the car. Could live without the looming, but dangling wires would look out of place and stand a good chance of getting chaffed. On models without the above features, the holes that the looming goes into will have plastic plugs in them to prevent water from entering the car when it rains.

2 Door lock actuators: Door lock actuator is basically an electric motor with a gear system attached to it so that the rod on the top moves up and down. General motors to save on manufacturing costs used the same actuator in many of it's 1980's products.

A common reason for failure of door lock actuators appears to be that the protective rubber boot gets brittle and cracks which lets water in. The newest thirdgen is over 10 years old, the oldest over 20 years old. Finding a used actuator that works when power is applied to it is one thing, finding a used one that will still work 2 or 3 years later is another thing. If you want to save yourself the frustration of having to replace your actuators a little while down the road, install new ones. If you watch the ebay auctions, new ones are often avaliable for under $40/each.

2 brackets that hold actuators to door shell (two different pictures of same bracket). Bracket like the actuator is shared with many other rear wheel drive 1980's general motors products such as cutlass, regal, monte carlo, caprice, etc.

2 "bellcrank" linkages that connect the actuator to the interior lock rod. Below are two shots of the same linkage, one is front side, other is back side. The linkage pictured below is the drivers door linkage, the passenger door linkage is a mirror image of the drivers door linkage. Linkage is an f-body camaro/firebird specific part, other  gm products such as fiero may have similar looking linkages but they are not the same and will not work in an f-body.

Relays: You can use a pair of generic aftermarket 30 amp SPDT relays, or you can use original equipment GM ones. If you choose the OE GM route, you'll need the proper GM connector and be aware that there are a couple of different relays used depending on model year of the vehicle.

The 82'-89' style that is located behind the drivers side kickpanel:

The 90'-92' style is located under the drivers side dash near the firewall:

Below is a universal aftermarket door lock actuator. To install, find a location to mount the actuator on the door where the interior lock rod is accessible. Then drill the door shell and bolt the actuator into place. The actuator will come with a clamp to secure the actuator rod to the door lock rod. Do not need the (original equipment) OE actuator, OE actuator bracket, or OE spring loaded linkage if you choose the aftermarket actuator route. However, you will still need the relays and wiring to the actuators.

The actuator setup used in thirdgens has proven itself to be very reliable and all the required mounting holes are predrilled in the doors so that the parts will only go in one way. Using aftermarket actuators will work, but issues that need to be considered include:

 
 

Optional Parts:

If you're adding remote keyless entry, it is optional whether to add lock/unlock switches to the doors. If you choose to add switches, you'll need the switches, switch sockets, switch panels, 4 small torx screws (2 each door) and some additional wire.

If you want switches with white lettering, choose the 82'-89' door switches. If you want yellow lettering, get the 90'-92' switches.

Below is a thirdgen door panel with the power door lock buttons installed and also an exterior electric power mirror switch.


 

Installation:

Below is the drivers door of a thirdgen f-body with the exterior sheetmetal cut away to reveal the door latch and linkage rods. In thirdgen f-bodies each door latch has four linkage rods attached to it that connect to:

the exterior door lock cylinder
the exterior door handle
the interior door handle
the interior lock slider

All thirdgen f-bodies regardless of whether they were factory equipped with power door locks or not have a u-shaped bend in the linkage rod that connects from the latch assembly to the door lock slider on the interior door panel. As can be seen by the picture below, the bellcrank actuator linkage assembly slips over the bend in the interior lock rod.


Here's another picture of the door from a different angle. The large black device towards the bottom pulls upwards and downwards on the bellcrank assembly. The bellcrank assembly then moves the lock linkage rod from side to side.


If you haven't already, remove the interior trim panel and start pulling and sliding all the handles and buttons you can find on the door. You'll quickly be able to identify the purpose of each rod inside the door.

Wiring:

As you can see below, the factory power lock setup gets power from two seperate circuits. Power for the actuators is provided by the "pwr acc" circuit breaker and power for the switches is provided by the "ctsy" fuse. Orange with black stripe wire powers rear window defroster, power seats & power lock actuators. Orange wire from the courtesy circuit powers a couple other items besides the lock switches including the cigar lighter, dome lights, and radio.

Might seem odd at first to see two seperate circuits for power locks, but keep in mind that circuit breakers automatically reset and are very good at dealing with high transient current draw accessories such as door lock actuators. By contrast, there is negligible current draw on the door lock switches, just a fraction of an amp to engage the relay coils. Is possible for switches contacts inside door to short to metal door shell, fuses are much better at safely dealing with this situation than a circuit breaker would be.

In the circuit pictured below with neither door lock switch engaged, both terminals of the actuator are held at ground. When a lock switch is pushed, one wire of the actuator is still held at ground but the other terminal is held at +12Volts which engages the actuator. Reversing the polarity (swapping which wire on actuator is +12volts and which is ground) will reverse the direction of the actuator and unlock instead of lock the door.

The setup pictured below is known as a "positive trigger" door lock system. Putting +12Volts on the LightBlue relay coil wire locks the doors, putting +12Volts on the Black relay coil wire unlocks the doors. Be careful if hunting for black wires for the lock switches, a lot of other circuits use black as a ground cable.


 

Below is a picture of the wiring inside the door. Towards the back of the door is the connector for the lock actuator, towards the front is the connector for the lock switch. The wiring is clipped to the metal door shell so it doesn't fall out of place and get caught in moving parts. Clips are brittle and will probably crack if you attempt to remove them from a donor vehicle. You've got a couple options for retaining the wiring, you can order new clips from the local gm dealer (holes are predrilled in the door) or you can use duct tape to hold the wiring in place.

The wiring runs from the back of the door to the front of the door and then through the rubber boot and inside the vehicle under the dash. on models without any power options in the doors, there will be a black plastic plug on the door and one on the body of the car where the rubber boot would go.

Other issues:

The actuator bracket is originally riveted to the door shell, but nuts and bolts appear to be an acceptable substitute if you do not have access to a suitable oversized 1/4" rivet gun. The linkage that connects the actuator to interior door lock rod is likewise riveted, but you can use nuts & bolts as well. Holes are predrilled in the metal door shell for the actuator bracket and actuator linkage.

On cars that do not have power locks, there is a factory delete panel where the lock switch panel would be. The delete panel is clipped into place, the panel with switches is held into place using two torx head screws.

From the factory, the door lock harness connects from the passengers door to the drivers side underdash area by passing through a plastic conduit secured to the metal inside the car underneath the windshield. To access this area, you'll need to remove the black dash pad on the top of the dash. Defroster duct work may get in the way, but you will be able to run the needed wires with a little persistence. If you do not want to remove the top dash pad, you could alternatively run the wires above the underdash panels and across the front of the radio pod.

Make sure to grease the latch mechanism while you have the door panel off. Grease is often broken down on thirdgens and requires high effort to lock/unlock the door. Lock actuators even if in excellent shape may be unable to overcome a sticky latch mechanism and as a result you will have symptoms such as lock rod only moving a fraction of the proper distance when you press the lock or unlock button. "White lithium grease" works excellent for this task, wd40 works as a good solvent for removing the old grease before spraying with white lithium grease. Some members of thirdgen.org have had such stubborn door latch mechanisms that they've needed to remove them from the door and soak overnight in solvent to get the old grease and other debris off.

Questions or comments?
Email me: [email protected]