Installing a Keyless Entry System

[CRSWA]

I didn’t think it would be worth writing this up initially because there are about a zillion different kits out there and the process likely will be different depending on which one you get. Someone expressed interest though, so I figured it might make a good starting point for someone else’s project.

For the record, I’m starting with a ’92 LJ78 and a completely generic keyless entry kit from Amazon.

There are a lot of wires coming out of the remote control box, but I’m only interested in the following:
▪ Positive and negative 12v wires to power the box
▪ The 6 output wires to the door control. 3 each for the open and close circuits (more on that in a bit)

The rest of the wires I just bundled up and hid behind the unit in case I want to make use of them later.

Powering the remote control box

After you take the driver side door card off, you’ll find the door control box in the lower rear of the door. I tapped into the positive and negative power leads in that harness to power my remote control box. No judgement about what type of tap you use, but the positive wire is blue with a red stripe and the negative is white with a black stripe. Once you’ve supplied power to the remote control box, click the remote a couple of times to make sure you can hear the relays clicking. You’re now done with the easy part.

Connecting the lock/unlock relays

Here’s a diagram of the door locking system:

It’s important to note that the door locking system is triggered with negative voltage, So the output of the remote control box should provide ground to the door switch. Each of the relays in the remote control box has 3 wires:
▪ A normally-closed input wire - terminate this one
▪ A normally-open input wire - connect this one to negative 12 volts
▪ An output wire - tap this one into the wiring for the door switch

Here’s what that looks like:

Don’t tap into the door switch wires too close to the connector or you may interfere with it’s ability to connect to the switch. Trace the wires back toward the harness a bit before tapping in. The Lock wire is red/blue and comes off of position 3 on the connector. The Unlock wire is red/white and comes off of position 4.

That should be it. Check to make sure all of the regular door switches still work when you’re done. Hope this helps. Cheers.

 

[kgrove]

I used this to add keyless entry in my case to a 1995 KZJ78. Here's a quick summary and a couple photos. I am by no means an expert... in fact I had this figured wrong until I paid closer attention to the post above.

I used the following keyless entry package. It was about $20 on Amazon. It claims to be able to also connect to your blinkers or flashers so when you lock your doors your indicator lights will flash, but I left that feature out as it would have required running wires from the drivers door to the dash. Maybe I'll do that later, but doubtful. I chose this one because it was cheap, got good reviews, and the key fobs looked to be the same brand as one I had on an earlier car that worked quite well. I can't say it works better or worse than another because this is the only one I've ever installed.
Amazon product ASIN B07JWF5GCS
key fobs:

wiring harness and remote control box:

wiring diagram (Figure C for negative trigger wiring diagram is the one suggested above that worked):

wiring harness with my summary of where to connect the remote control wiring harness to the KZJ78 Door Controller wires by color code):

wire taps for the battery power (mostly blue w red stripe on far left), unlock (red-white wire in middle), and lock (red-black wire towards right). Behind you can barely see the ground wire (white-black) where I connected the black, yellow, and yellow/black wires from the remote control box to the ground / battery negative wire.

I should have taken photos of the door with the panel off to show the location of the Door Control Box, but I forgot. When you remove the drivers door card, it's in the bottom right corner of the door.

The trick here is to ground the yellow and yellow black wires along with the black ground wire. I used the white-black ground wire going into the Door Controller Box. The Orange and Orange-black wires are not used. I did not use the brown (parking lights), green (window rise), or blue (trunk release) wires either - just wrapped them up in case I wanted them later.

There was room just to the left of the Door Controller Box to tuck the remote control box behind the wire bundle but on the door card side of the vapor barrier. I just taped it into place. There's probably a more secure way to mount this give the door will bang shut many times over the years.

If I were to spend more time with the system, it could probably be better mounted under the dash or behind the drivers side kick plate. This would allow for easier access to parking lights so the car would flash when the door lock button was used and would make for a more secure long-term mounting location for the remote box. This would either require running wires through the door to connect to the lock (R-B) and unlock (R-W) wires on the Door Controller box, or maybe those wires already run through the door as they need to get from Door Controller box to the other three doors. This would be great research for the next guy to tackle this project.

As is, it is much nicer to have a pair of keyless fobs as I felt like I was back in 1995 having to use my key to lock and unlock the car. And it only cost $20 and a few hours of work (should take less time for the next guy... would have taken me less time if I had paid more attention to the post in front of this one).

 

[Jern]

Thanks for the write ups above guys, I got the same kit and worked like a charm. I did however snap the door linkage clip doing it in the dark, so now waiting for that part to come before putting the door card back on.

This method is roughly 1/10th of the cost if you get a plug and play kit and is exactly the same hardware. Also skipped the indicators lighting up at this stage.

Cheers

 

[kgrove]

Thanks for the write ups above guys, I got the same kit and worked like a charm. I did however snap the door linkage clip doing it in the dark, so now waiting for that part to come before putting the door card back on.

This method is roughly 1/10th of the cost if you get a plug and play kit and is exactly the same hardware. Also skipped the indicators lighting up at this stage.

Cheers

View attachment 4155843

One suggestion based on a second install I did (different KZJ78) using the same aftermarket kit... Install the box in the footwell behind the kick panel instead of in the door. I had some problems getting the box to fit in that hole without interfering with the window movement. Installing in the kick panel means you have to fish wires through the door harness to make these same connections, but if you plan on connecting to either the flashers or horn so you get confirmation the key fob did it's job (or you're trying to find your car in a parking lot... not that Ive ever lost mine), you'd be doing that anyway. I haven't connected up either yet, but have been planning on doing so soon as I have some work to do on the steering column anyway. Locating the box in the kick panel has more room and puts the unit closer to the flashers or horn. There might be a way to do that and tap a wire already in the kick panel and not have to remove the door panel, but I didn't locate it.

Small review of the aftermarket unit I used: It has worked great for multiple years. That said, I don't like the fobs themselves. The buttons aren't protected or recessed, so I frequently find the door locks cycle when the keys are in my pocket and I accidentally press the buttons - digging for something else in my pocket, lean on the car to reach something, etc. In hindsight I'd look for a unit where the buttons weren't so easily pushed on accident.

 

[Jern]

Hmm yeah I might look into that, I still have the door card off so wouldn’t be too much trouble and their is plenty of wire.

My key fob is different to yours the buttons are slightly recessed so haven’t had that issue, I must say I’m feeling very modern not having to get the keys out every time!