Tech: Upgrade your keyless entry using factory parts

[iroc86]

Most of us have enough trouble getting the power door locks to just work in these old rigs, but I recently performed a simple upgrade to get a functioning keyless entry system.

I'd like to mention that I came across the original idea from a post on JeepForum.com. The author of the post upgraded his ZJ's IR keyless entry system to a more modern RF version using Chrysler LH sedan parts. My conversion is very similar, but there are a few FSJ nuances. I suggest reading the JeepForum.com post for the background information, as it contains a wiring diagram for the LH keyless entry module and programming instructions.

The following procedure is for FSJs originally equipped with keyless entry systems. There is a wiring harness in the roof behind the overhead console, as well as two relays behind the dashboard that activate the door lock actuators.

One word of caution, if a bit obvious: I would not bother with keyless entry in a FSJ if your power door locks don't work properly to begin with. Mine didn't -- the door lock actuators were only seeing about 8 V when energized. I wired a pair of relays in each front door, along with a dedicated power wire, to reduce the voltage drop and provide a full 12 V to the actuators. I left the rear actuators alone because they worked properly.

My remote keyless entry (RKE) module came from a 1995 Chrysler Concorde. I made an adapter harness by cutting the connector off of the IR module and splicing into the Concorde wiring. The wiring conversion is as follows:

B+: PK (FSJ) -- PK (LH)
Ground: BK (FSJ) -- BK (LH)
Lock: GY/VT (FSJ) -- PK/BK (LH)
Unlock*: PK/GN (FSJ) -- PK/VT (LH)

* Using Driver's Door Unlock function

The RKE module is designed to open the driver's door with the first press of the Unlock remote button, and the rest of the doors with a subsequent press. I didn't want to wire my driver's door separately, so I used the Driver's Door Unlock output to perform the unlocking function. This ensures that all of the doors will unlock on the first press of the Unlock remote button. (Note: in the JeepForum.com article, the author suggested installing a diode if wiring the RKE unlock function in this manner. The concern is that the door lock switches can back-feed a voltage to the RKE module and short it out. Fortunately, a diode isn't necessary on a FSJ because the keyless entry relays are not energized when the door lock switches are used.)

Here is the wiring diagram for the factory FSJ keyless entry system, borrowed from Tom Collins' website. The red box shows the connector on the IR module that needs spliced into the RKE module.





Connecting the RKE module to the existing wiring provides a level of functionality equal to the stock FSJ IR system (though with better range). The RKE module also has outputs for a trunk release, horn, illuminated entry, and other things. I chose to wire the parking light circuit into the RKE module so the lights flash any time the vehicle is locked or unlocked. Luckily, the parking light circuit can be reached from the overhead console -- the compass and temperature display uses it as an input for its dimming feature. The wires are only AWG 20, but they're capable of handling the load (especially for such a short duration). The parking light circuit in my '89 GW draws about 3.5 A.

In the diagram below, The yellow wire supplies power to a pair of relays which are controlled by the lock and unlock outputs from the RKE module. For either a lock or unlock operation, the blue wire is switched to +12 V, which momentarily energizes the parking light circuit. In all other cases the blue wire is left floating.







After wiring everything up, I was able to fit the RKE module and relays into the overhead console without removing the old IR module. The little black dome is still there and it doesn't look any different than stock.

I was surprised by how well the system works. The range is pretty good too, about fifty feet. Grand Wagoneers may have been ahead of the curve with keyless entry in the late 1980s, but I think it's worth upgrading to something more reliable. For the cost of the RKE module and remote (about $25 total), it was cheaper than buying an aftermarket keyless entry system... and it just feels good using factory parts.

You can view a short video of the system here: http://www.youtube.com/watch?v=NURPlMv9fUo

[addicted]

I like it!

[2ToneBluJ10]

Nice write up.

[grandwag89]

Very interesting, I see another upgrade in my future.

[Brizio]

Cool! Unfortunately I don't understand too much in electric stuff, so I can't do it myself...

[Wagoneerlover]

Great!! Another upgrade I can do. Thanks for putting this out there for everyone!!

[ajminla]

great post.
I was doing some research on my own about this same issue.
I was thinking that it wasn't too likely that Jeep changed everything in the Grand Cherokee Line in '92 and '93. Perhaps '93 Cherokee replacements could work. There seem to be plenty avail on line etc.
Speaking to one of the remote vendors (originalkeyless DOT com), he confirmed this stating that the system was identical in 93-95 Grand Cherokees. Remote receiver is identical, just a new 2 button remote. So maybe this is also another option.

I have to work on my locks at the moment anyway before moving forward.
My 3 of my 4 locks will lock, but none will unlock with the power switch.
Not yet sure of what i need to replace.

[iroc86]

Thanks! Glad you're all finding this useful.

At least one member PM'd me about the door lock relays I installed, so I made up a schematic in case anyone else was curious.

Some background info: the door lock actuators have two wires that are normally grounded. When the lock/unlock switch is pressed, one of the wires is switched to 12 V depending on the direction of the actuator (lock or unlock). On my Jeep, the actuator was only receiving about 8 V, even after cleaning the switch contacts and checking for shorts. That's not enough voltage to operate the locks, but it's enough to (barely) operate a relay.

You'll need two 5-pin SPDT automotive relays per door. The relay connections imitate the switch wiring, but all of the current flows through the relay instead of the switch. The door lock motors are still normally grounded.

After making this modification, you'll find your locks are considerably more powerful. In fact, they're just plain loud!

I only added relays to the front doors because my rear locks seemed to work fine. However, removing the current load from the wiring has actually made the rear actuators stronger. I haven't checked the voltage back there, but I'm sure it's greater than 8 V now.

Note: the BR and DK BL wire coloring shown in the schematic below should be the same for all of the doors. The '90 wiring diagram I was referencing shows different color wires for the left rear lock actuator (go figure), but the premise is the same. Just make sure the same color wires go to each relay, otherwise your locks will operate in reverse for that particular door.

EDIT: make sure to add a fuse on the B+ circuit. 10 A ought to suffice.

[cn6149]

For someone who never had keyless entry and would like it, I once ordered online a kit for my wifes camaro. It came with everything to do a two door including 2 actuators and remote fobs for about 80 bucks shipped. The instructions were clear and the upgrade pretty straitforward. Well within the ablity of most on this forum.

[JeepJeepster]

Sorry to bring this back from the dead, but its one of the few threads Ive been able to find on keyless entry. I would love to get this working again in my 89 that DID NOT come with the key fobs. Idk why people always lose the key fobs and the cargo covers, but those two things never come with used vehicles.

Anyone tried the 93-95 keyless entry? I have a 94 and several keyless remotes, Ive not tried training them to the grand wagoneer yet but I will when I can.

I also have a spare overhead console from a 95 ZJ with the IR eye in it. Could try taking that out and putting it in the FSJ overhead.

ohh and also they switched to RF RKE in the 96-98 zj's. It may be possible to do the same thing that the OP did but with a 96-98 ZJ RKE module.

[acct21]

Anyone tried the 93-95 keyless entry? I have a 94 and several keyless remotes, Ive not tried training them to the grand wagoneer yet but I will when I can.

I also have a spare overhead console from a 95 ZJ with the IR eye in it. Could try taking that out and putting it in the FSJ overhead.

ohh and also they switched to RF RKE in the 96-98 zj's. It may be possible to do the same thing that the OP did but with a 96-98 ZJ RKE module.

If you have the overhead console and the board in your '89, you can get a fob made from these folks :

http://www.thejeep.com/pilandcode.html

Whether or not you go this route (or the '95 ZJ route) you'll still have an IR opener that doesn't work much farther away than standing at the side of your Jeep.

I've replaced mine with the module out of a '94 Chrysler LHS (using this exact write up), and the remotes are cheap, plentiful, and can be reprogrammed without any tools. I ran a separate wire (and relay) to the driver's door lock so one push unlocks the driver's door; two pushes unlocks all of them.




The '96-'98 ZJs have the RKE as part of the passenger door module. I don't know if that will work separately or not.

[iroc86]

(OP here.) I second the notion to avoid the factory infrared keyless entry systems. Though I have not tried it myself, I've heard countless reports of reliability issues and short range. Being IR, you need a line of sight to the receiver in the headliner. Think TV remote control.

Many mid-'90s Chrysler vehicles came with usable RF modules, not just the LH model that I originally posted about. When I initially researched this modification, I attempted to use ZJ parts, but it didn't work. The module required dealer programming and it seemed like a hassle. These fobs can be identified by a red "panic" button in addition to the unlock, lock, and trunk buttons. I suppose it's not impossible to make work, but I couldn't justify the time just to have a panic button that I'd probably never use.

I've also noticed that some GM keyless entry systems from this era may be usable. The modules are made by the same company (TRW, I think) and the fobs look similar. The wiring is almost identical, too. It might be a decent alternative if the Chrysler stuff is hard to find.

[adzam]

I retrofitted a Viper 211HV about 2 years ago using the wiring diagrams from this same post. The best part of the Viper, is that its $35.. Shipped.

The Viper is about as simple as simple gets, and the range on the remotes is really really good. Best part of all, is that the Viper remotes can be found on Ebay for cheap if you need a replacement.

I've wanted to use the additional channel on the Viper to roll down my rear window, but I have not wanted to take everything back apart.

[iroc86]

I've wanted to use the additional channel on the Viper to roll down my rear window, but I have not wanted to take everything back apart.

That's a good point. Like the Viper unit, the factory RKE module supports an auxiliary output (trunk release). In a later iteration of this conversion, I used this output to roll down the rear window with a pair of Ford "auto-down" window modules. A quick and dirty 555 timer circuit shortened the pulsewidth from the RKE module to make it all work. The rear window went down with the trunk button and retracted upon locking the doors.

[racegas]

Relay Location

I'm trying to find the factory relays that control the power locks. I have read that they are behind the dash, but can't find any reference beyond that. I have the Factory Manual and the section on Power Locks doesn't even mention them. Can anyone give me an idea as to what I am looking for?

I've got power at the switch, but am not hearing the relays clicking when I move the switch.