Keyless Entry

After getting back to Park City, my daughter and I went for a ride and she asked what I was doing putting my key in the door. I really never gave it much thought because all of my other classic cars don't have keyless entry, but I was using this as a daily driver. It is really kind of a pain unlocking each door. 

That got me thinking, how hard is it to install keyless entry into a car? The door panels were already off to lube the windows and so they could be recovered. How hard would it be? Turns out, not that hard at all. Here is what I did.

First you need door actuators. Basically these are push/pull devices that hook up to your door locks, mount to the doors below the locks and push up with a positive 12V DC power and pull down when the polarity is reversed. heavy duty actuators are really not that expensive. Universal Car Power Door Lock Actuator can be purchased on Amazon for as little as $5.00 each.

The thing is, you will still need relays, inside switch and if you want it to be remote, a radio receiver and dongle. Turns out, there are some alarm options that provide the entire kit in one package. Two dongles, a receiver, 4 actuators and even an alarm. I selected the CrimeStopper SP-101 Car Security Alarm & Keyless Entry System with (4) Car Power Door Lock Actuator Motors form Amazon for about $45. I also got 6 SPOOLS 100' Feet 16 GA Gauge AWG Primary Remote Wire Auto Power Cable Stranded from amazon to run to each door. 

Bellows on Driver's Door

The hardest part was not mounting the actuators, it was getting power into the doors. My front doors never had power so there is no accordion to run the cables. This meant creating a 1" hole on the door and the jam, priming and painting it then installing an accordion. Euro Truck Importers sells the Mercedes Door Wiring Bellows PN: 1238210697 for about $5.25. That allowed me to run the two wires into each door for the actuators. For the back door, I just snaked the cable through the existing wiring harness. 

It was very easy to install the actuators. I pulled off the door handles by removing the bolts to expose the lock. There I just attached the clamp that came with the actuator on the end of the locking plate. It took some work but it just fit. Then I installed the rod and mounted the actuator near the bottom of the door, drilled two small holes, primed and painted the holes and mounted the actuator on the inside of the door. I tested the actuator with a 12V DC supply before moving onto the other doors.

Wiring Diagram for Alam and Power Locks

I then installed the keyless controller behind the panel next to the ignition switch and added an Installer Essentials Dual relay behind the glove box to control the power locks. I wired the alarm to the L&R parking lights and even came up with a way to have the dome light come on when unlocking the car. This required and additional relay and a diode. (See diagram) I was able to tap into all of the wire I needed to access from the fuse box under the dash on the driver's side. I installed a new fuse box for constant 12V DC behind the glove box for the alarm, power locks and new subwofer amp. The alarm siren was installed under the hood on the drivers side. 

Behind glove box, showing sub amp and lock relay. 

When done, I ran wires under the carpet from the front of the car, along the lower door jamb, up the side pillars, through the side of the car to the rear door. I also ran new speaker cable at the same time for the rear speakers. The controller for the alarm was installed behind the dash panel near the ignition switch and the door relays behind the glove box. I found letting the antenna from the alarm hang down under the dash extended the range of the keyless entry. I repurposed one of the spring switches in the dash and use it as an interior lock/unlock switch. Make sure this is a spring loaded switch as leaving the locks in the locked or unlocked position will drain your battery and burn out the actuators. 

I'm SOOO happy I did this. Now it is easier to find my car in a large lot, easy to unlock all the doors and they automatically lock when I start the car! Most importantly, my daughter does not look at me strange when I unlock the car!