Delco power door lock retrofit information.

This pertains to the electric door locks used on 80's and 90's GM cars and trucks. There were many different button and keyless receiver combinations used by GM to control the same relay and lock actuator setup. This information pertains to setting up a stand-alone power door lock system on a vehicle that didn't originally have power locks.

Parts location on donor vehicle.

Directional Relay: Behind glove box clipped to inner structure of dash assy. No tools may be needed
Actuators: One in each door, you will need a cordless drill and 3/8 bit to drill out the rivets. Screwdrivers, 7MM socket, and wire cutters needed. Varies by car make and model.

Circuit operation/ grounded signal modification.

GM used a positive battery signal from the switches to the relay to actuate the relay. Most anyone who retrofits power locks is doing this as a step towards going keyless. All aftermarket keyless/ alarm receivers provide a switched grounded signal. I have shown the circuit in a grounded-signal configuration. If you are adding keyless entry to a FACTORY GM power lock vehicle, and you need to convert to a GROUNDED signal the change is very simple. It is a 2-step process.

Step 1: Convert the directional relay to respond to a grounded signal. Unplug the directional relay and swap the power and ground; and lock/ unlock signals at the relay. Accomplish this by removing the terminals from the connector using a Metri-Pack pin removal tool or similar item.
-Interchange Power and Ground supply to relay. Swap C (org) and D(blk-large)
-Interchange Lock and Unlock signals. Swap A (blu) and F(blk-small)

Step 2: Convert the door switches to provide a grounded signal. Remove the door panels on every door with a power lock switch. Locate the wire going to pin B on the 3-terminal lock switch. It is an orange wire. Cut it off and carefully insulate the wire going back into the door harness. This is a hot wire and will blow a fuse if it goes to ground. Install a ring terminal to the remaining orange wire from the B terminal of the switch. Ground this wire to the door using a self-tapping sheet metal screw. Test the system and insure the locks still function and the operation is not reversed.

Schematic and ladder idagram at page bottom.

Installation on Non-GM or Old vehicles.

I have retrofitted these actuators and relays to 2 vahicles that weren't a native application. One was my 1972 Nova, and the other was my company vehicle, a 2002 Ford F450 Super Duty. On both of these the door latch mechanisms had an additional linkage hole in the lock button arm. This linkage hole was apparently for a factory power lock linkage. Even in 72 they had powewr locks; imagine that! The installation into the Ford door is outlined here with pictures.

Remove door panel and carefully tie back sound insulation sheet. There is a hidden screw under the red reflector, front section of armrest, and window crank handle. Once these are out, lift straight up on panel to remove it.

Drill appropriate holes in door skin to mount actuator. Location not critical as long as actuator rod moves in line with lock mechanism arm and window can roll down without hitting anything.

Linkage rod can be fabricated from non-threaded 1/8" steel rod. A welding rod was used here, after flux coating removal. The ends of the rod need square bends, not U-bends. The rubber isolator in the actuator will deform and allow the rod to disengage if it is riding on a curved rod! Voice of experience! Details can be found here.

Fish the wire through the door hinge area, following the factory harness through the flexible rubber boot. You may have to pop the boot out of the body to get it through but there is plenty of room.

Route L and R actuator wires to the relay and connect keyless/ alarm module to the appropriate connection.

I don't have a manual lock switch in this truck. You either have to press the lock in by hand or use the keyless remote. I didn't see any real need in a manual switch for the locks. But if desired I could go to the junkyard and get a Ford armrest cap including the factory-correct switches. They could then be tied in to the same points as the keyless/ alarm lock and unlock signals.

There is a dust-boot missing off the actuators in these pictures. It is optional and will improve actuator life. If anyone has a source of these please drop me an e-mail! See main web page for my address.

Latch mechanism in door of 2002 Foed Super Duty showing home-made power door lock actuator rod connected to mechanism.

Delco actuator inside the door of a 2002 Ford Super Duty pickup. Camera is held inside the door with door panel removed.

Above left is the directional relay, with connector and connector locking clip. Right is actuator with connector unplugged. Relay terminals are labelled A through F and the letters are embossed into the relay up inside the connector socket. They are visible with connector unplugged.

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