By Grant Jump on Sunday, September 30, 2001 - 12:40 am: Edit

I am in the process of changing the alarm that is fitted to my vehicle. The problem I have got is trying to locate the central door locking relay. Is it part of the drivers door actuator which is the only logical place left for it to be?
Any ideas??

By Shane C. (Qsiguy) on Wednesday, October 03, 2001 - 10:41 pm: Edit

I believe there is just a switch in the driver door, no actuator (meaning the driver door won't lock itself). I think there is a relay or control unit for the locks but I don't know where it is. I would get inside and lock and unlock the doors and listen for the clicking under the dash on either side and/or behind the radio area. I own a car alarm/stereo business but haven't ever had to find one. If you are trying to add keyless entry with an aftermarket alarm what you have to do is add an aftermarket actuator to the drivers door and when it locks/unlocks it will lock/unlock the rest of the doors via the oem locking system. We sell those actuators for $20 and to wire it up you'll need 2 SPDT relays.

By ken on Thursday, October 04, 2001 - 05:08 am: Edit

It's been a long time since I had to deal with a 90' rover. is there a switch to activate the doors? if so where are they? if they are in the doors then check the kick panels for the same wires and test there polarity. if you push the button and the polarity shows + as it locks and unlocks then it's a Pos. system and just hook up the wire there no need to find the relay pack. if it's - then you have to cut 1 wire if you loose function only in one direction then it is a neg. system and the install is the same as before. if you lose all function then it is a reverse polarity system and you will have to add your own relays. I the lock is the switch as stated in the previous post then that would be your other option. of all my years doing alarms I HATE DOORLOCKS!!! Theres actually alot more systems but it's very doubtfull rover utilizes them so they are not worth mentioning.

By Shane C. (Qsiguy) on Thursday, October 04, 2001 - 07:23 pm: Edit

The switch(s) I am refering to is built into the lock mechanism inside the driver door. When you push in the lock it hits the micro switch in the mechanism and tells the other doors to lock or unlock. We have always added an aftermarket actuator to the driver door and all the other doors will lock/unlock when that door locks or unlocks. That way you just have to wire up the add-on acuator to the alarm.

All this said, today I checked it out a bit on my 95 Disco and realized that the driver door lock does seem to pull itself down or up when I lock/unlock it manually so it may, infact, have the ability to lock itself with the proper wiring. I am going to pull it apart tommorow and get the wiring info as it is not in any of my trade manuals. I do hear a relay behind my glove box clicking when I operate the door locks so at least on my 95 Disco the proper wires may be located there. I'll put up the info for mine tomorrow. Don't know if it'll match the '90 but it should.

By Shane C. (Qsiguy) on Saturday, October 06, 2001 - 05:56 am: Edit

OK, I did some research and have the door lock wiring info for most LR's and I confirmed this on my 1995 Disco. They use a one wire door lock trigger system. The wire will be behind the drivers kick panel and is either Yellow w/pink stripe (like mine) or Yellow w/red stripe. Here's how it works. If the doors are unlocked, cutting this wire will make them lock. If the doors are locked, grounding this wire will make them unlock.



Requires one 12volt 30Amp SPDT relay and one diode, and an alarm or keyless entry system with door lock outputs (this diagram is for alarms with neg (-) door lock outputs, which are the most common.