Keyless Remote

(Brian Ulmer)
The 20V cars were never offered with a keyless remote option. However, it is possible to install an aftermarket system that integrates with the power locks and stock anti-theft alarm. One very good reason for doing this (besides the convenience), is that you take much of the load off of the lock cylinder links which are known to break often. The following is a guide for installing one particular keyless remote system. Hopefully, these procedures will be helpful to you even if you choose a different brand or model.

The remote entry unit used in this application was an AutoLoc KY3750 ($90). Don't let them sell you an extra actuator. You won't need it. Other brands can probably be used, as they are all pretty similar. You will also need two 12V DC DPDT relays (Radio Shack P/N 275-0218), 20+ feet of wire, around 16 female spade connectors, electrical tape, a few plastic zip-ties, wire cutters, and a crimping tool. You'll also need a soldering iron and solder or some wire nuts for splicing. As always, you should disconnect your battery ground before playing with your cars electrical system. Be sure you know how to unlock the radio!

Access to Central Locking System
To access the central vacuum unit you must remove the side panel on the right rear passenger side (the one with the speaker grill and storage pocket in it). To do this you must first remove the bottom cushion of the rear seat (2 screws), then fold down the rear seat back and remove the side bolster by unscrewing the striker pin with an allen wrench, then pull down on the bolster to remove. Try to take note of the approximate position and length of the striker pin, because they are tough to line up when you reinstall them. With these pieces off, you should be able to now remove the four screws that hold the side panel on then lift up on the panel. The vacuum pump is enclosed in a block of insulation against the outside body panel and is attached to the metal frame by a couple of plastic tabs. It is inside a cavity at the upper right. Wiggle the vacuum pump out and disconnect the wiring harness.

The wiring diagram below should be all you need to get most of this together. Here is the principle behind this system. The factory central locking system is triggered by switches inside each individual lock actuator. When the drivers door is unlocked, lead #4 on the central locking vacuum unit you just removed is connected to +12V through the actuator in the drivers door. When the drivers door is locked, the actuator is moved and switches lead #4 to ground (0V). This triggers the central vacuum unit to lock the entire car. The car remains locked until a door is unlocked, bringing lead #4 to +12V again and triggering the central vacuum unit to unlock the entire car. We will now install two relays, one lock relay and one unlock relay to trick the central vacuum unit into thinking that the drivers door has been locked or unlocked. When the remote entry is at rest, the central locking wiring is connected as it was before this installation with no break in lead #4. Only when the lock or unlock button is pressed does the relay momentarily connect lead #4 to ground or +12V, triggering the system to lock or unlock. One note, the AutoLoc unit I received would only give a one second pulse when the lock button was depressed but would trigger indefinitely as long as the unlock button was pressed. I had intermittent problems locking/arming the car until I swapped the lock and unlock leads, giving the lock/arm feature the longer pulse. Therefore wiring diagram reflects this change. The connections with the relays were made using crimp-on female spade connectors. Get the kind with plastic insulating covers to prevent short circuits, they will be pretty close together on the relays. Finally, I used the constant +12V and ground from the vacuum pump to power the remote entry unit by splicing into these wires. It may be better to run dedicated +12V and ground wires instead but I've had no problems with this setup. It's best to solder these connections but you can use wire nuts instead. Finally, make sure to cut your wires long enough to allow the remote entry unit and relays to be mounted out of the way during reassembly.

Anti-theft Alarm Activation
The remote entry unit can also be used to arm and disarm the anti-theft system. The system is armed by grounding the #8 lead on the 12 pin connector and disarmed by grounding the #3 lead on the 12 pin connector. The anti-theft system controller is located behind the left side trim panel in the rear hatch. You must remove the spare tire, jack, and the stop for the hatch cover (2 screws) to remove this trim. You should be able to push the moderately flexible panel down and away from the molding at the top. Once removed, the anti-theft control unit is located between the frame and the outside body panel. It's the one with two wiring connectors (one 12 pin and one 3 pin). Remove the unit and disconnect the 12 pin connector. You simply need to splice two wires, one into the #8 lead and one into the #3 lead. These then connect to the lock and unlock relays as in the wiring diagram. I ended up running these wires behind the trim panel and under the rear seat to keep them out of the way.

Finishing Up
You will now want to reconnect your battery and test the system. If everything works as planned you can wrap electrical tape around the relays and connections to prevent them from coming loose. Return the central vacuum unit and anti-theft system controller to their original locations and mount the remote entry unit and relays close to the central vacuum unit with plastic zip-ties. I got the best remote reception by running the antenna wire along the bottom edge of the window under the trim. Reassemble the side panels, seat bolster, and seat.

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