Anyone have experience with 1996 ZJ RKE Alarms

My RKE (fob) alarm system is tango uniform, complete malfunction, gauges are on and off, disabler is erratic, etc. I helped my son fix the same problem on a later model by replacing the PCM and removing the SKIM Module.

This model uses an RF Transmitter fob rather than a chipped key. I think the receiver module is integral to the passenger door window and lock control. And the alarm arms and disarms from lock movement.

Is this type repair feasible for a 1996 Security System?

Thanks,

 

I think I have this figured out. First, some background.

The 1996 GC Limited alarm system is a rather simple non-SKIM system the key and FOB are NOT really part of the system. I will explain that in a minute. The alarm/disabler is set or cancelled by three 'Key Switches', micro-switches located at the inside end of each lock cylinder. They are lock and directional specific. The switch simply grounds the now (in)famous yellow/purple wire. The rest of the alarm/disabler is entirely contained within the PCM, and can be erased.

Some practical dope; The alarm is cancelled by a single closing of any one of the three door switches, in the unlock direction with the key. If you cannot get the alarm to reset with the key at the doors or lift gate, you have switch problems same as me. They wear and become unstable after 26 years! All three of my switches exhibit signs of inconsistency due to wear in about the same frequency as my alarm issues. I will post some photos of the part and wear. To cancel your alarm pop a door panel follow the wire harness attached to the back of the lock cylinder to the first connection. It is labeled Key Switch. Disconnect the connector and briefly jumper the two wires opposite the switch harness.

I've been told if you permanently jumper that wire it will prevent the alarm from setting. Perhaps, I may try that later but it will NOT reset the alarm or disabler once activated. Reset requires a "digital" signal, a quick grounding once.

I removed all three micro-switches from the back of the lock cylinders and installed very discrete push button switches in the doors. It is my hope I can duplicate the digital signals use this work around to maintain the alarm functions manually. I'll let you all know how that works. In any case I have a reliable way to reset the alarms in the even of a false trigger in the future.

A quick note about the micro switches: I manipulated all three switches manually and with the power locks after connecting meters to each switch. The results observed suggest two closures of the switch on the drivers door in the lock direction and one closure in the unlock direction. The hatch and passenger door had a single closing in the unlock direction. The logic seems to make sense but my driver side switch is worn considerably and the two closures my be part of the defect. In any case, I only mention because it seems logical

The key and remote are part of the system only to the extent they manipulate the lock cylinder thereby closing the micro switch. The panic button signal is a burst of closures programmed into the power lock on the passenger side.

Hope this helps somebody

 

This is the culprit. There are three of them; one attached to the inside of the drivers door lock cylinder, passenger door same same and one at the rear hatch lock.

Notice that one edge of the "triangle recess" is missing. All three of mine were essentially in the same condition. As you can imagine the behavior of the switch is compromised.

In my case; I rigged all three switches to a meter and manipulated them with the power lock and individually 300 cycles. In every case every switches failed to close an average of 14% of the cycles. That corresponds exactly to the rate of alarm malfunctions I was observing and moreover, the lift gate came in a distant last in malfunctions consistent with my theory of mechanical wear in the micro-switch.

 

Before anyone asks, that is indeed sticky back craft foam from Hobby Lobby, It is far and away the finest sound deadener I've ever used and it's dirt cheep. I re seal all the door openings with it and run it underneath every wiring harness. I like quiet, leather seats and air-conditioning. Did I mention I like quiet?

 

I'll up load pics and instructions a bit later. Right now I need to correct some information.

There is a parasitic signal in the power lock circuit even when the alarmed has been erased from the the PCM that appears to reload the alarm much the same way the SKIM works and you will be back to square one. Take advantage of that. I installed two discrete momentary switches; one in each door to simulate the worn lock switches mentioned in the earlier post. As it turns out, you really only need one for the drivers side but we all have some OCD to one degree or another, mine is symmetry.

In the drivers door you will encounter the (in)famous yellow/purple wire, forget the kick plate. Get in the door and pop the switch off the back of the lock cylinder and follow it back the the first connector where you should see the yellow/purple and black wire. Wire a momentary switch across the wires. Operation as follows:

To set the alarm: Use the power lock and close the door. The red light will start flashing rapidly and slow in about 30sec. At this point if you open the door the alarm triggers- one press of the switch cancels the alarm.

To Lock it up w/o setting the alarm: Use the power lock and cancel the alarm before closing the door. You can also hold the switch while setting the power lock, probably the source of the "yellow/Purple hack". I question the sanity of creating a permanent dead short but it's your Jeep. In any case one press does the trick, either during the power lock cycle or after it matters not.

I would like to say something else. The folks that programmed, reprogrammed and reprogrammed my PCM were patient and helpful. They answered my phone calls or called back that day and spent quite a bit of time answering questions for me at least a dozen calls. I won't mention them publicly but if you drop me PM I can point you their way. They were super helpful.

 

Couple of loose ends to tie up an we'll call it complete. First, this is the switch I used it's actually very low profile and discrete. It allowed me to maintain the alarm even though the oem cylinder switches malfunctioning and unavailable through normal channels. This is a reliable way to cancel and/or operate the alarm



This is how it looks installed in the passenger door



The drivers door



The wiring harness.



The infamous yellow/purple wire. The OEM switch will have one green and one black the connect to the yellow/purple and black respectively.




I put a switch in each door. It isn't necessary a single switch in the drivers door will suffice.