EASY to install keyless entry in W124/W126
 

Did it this weekend. It was a LOT easier than I thought. First of all, your keyless entry unit MUST have a ~3 second unlock pulse capability and should have a three wire connector, usually the wires are blue, red, and green. You need to connect these to two FIVE pole relays, with pins 85, 86, 87, 87a, and 30. See diagram below.

Remove the circular plug on the vacuum lock pump. Cut the blue wire. You now have a "pump side" of the blue wire and a "door lock side" or the blue wire. Follow the diagram.

Now the fun part! Getting the parking lights to flash upon lock and unlock. You'll need two more of the relays that you used above. I'm assuming you already know how to get behind the headlight switch (which involves removing the underdash) so we'll skip that part...

Wire them as such:

Relay # 1:

* 87 & 85 : Light Output from alarm/RS unit
* 86 : Ground
* 30 : To left side of parking lights (terminal 58L)
* 87a: NOT USED

Relay # 2 :

* 87 & 85 : Light Output from alarm/RS unit
* 86 : Ground
* 30 : ToÊright side of parking lights (terminal 58R)
* 87a: NOT USED

(diagram below is for unlocking /locking only)

speedy300Dturbo

thanks, this is great. Do you have a parts list and rough $ estimate?

Keyless entry unit: $40 (from ebay)
Miscellaneous wires: $3
Wire crimps: $2
Additional relays: $10

Total cost, $55. :)

where did you get your relays?

Relays available at any decent auto parts store. As for the alarm working properly, it works the same as it did prior to the installation, because they keyless entry sends a signal through the blue wire (drivers door lock) and (un)locking it with the keyless is basically the equivalant of locking / unlocking the driver's door with the key.

My car has the typical if you unlock the car from the drivers door, the alarm might go off. If somebody like me hooked the keyless up to the drivers door like you, would I still experience this problem, or would that part of the faulty locking system be no factor? Thanks


Chris

speedy300Dturbo, do you have the exact brand/model name keyless entry unit?

Thanks!

ranger,

this is a "fix" for the bad tumbler problem you describe...

Benzwood: I got a very basic Crimestopper unit, the model is CS-845RKE. It has the 3 second door lock pulse time (to run the vacuum pump) but it was not advertised as having it. I think that most of the Crimestopper units have it.

Here's a unit that has 2 relays built in:

http://www.seco-larm.com/SLI830.htm

I saw one on Ebay for about $40. Do a search for 'seco-larm'.

the problem with those with the built in relays is that the relays are not wired for MB as in the diagram shown at the top of this thread. they are wired on the pcb to address most applications except MB - can't have it both ways. to re-wire for MB may require some surgery on the pcb. the only way to have a truly "universal" unit of this sort is if they built it so that the relay connections are reconfigurable...

Lock, but no Unlock
 

I got everything on the keyless entry/alarm working except for the unlock. Any ideas? There are a total of 6 wires in the round vacuum lock plug. Did I splice into the wrong blue wire? What else could it be?

Thanks.

I installed keyless entry on my 1991 190E already. Next project is to install flash lights. Any suggestions where is the good place to put both relays to make flash lights? thanks

Now, i installed the keyless entry unit beside the vaccum pump (under the rear seat)

I just hooked the +12V flashing light trigger to the left tail light, really easy if you have the keyless unit installed in the trunk.
Just remove the light cover, unplug the 8-pin connectoor, snap off the black cover on the wire plug to expose the pins, find pin #6 (gray/black tail light wire) and solder your wire to the back of it. Bam, all four parking lights flash when you hit the keyless button.
This is for a '91 300SE, so check the wire color to be sure you use the correct tail/park light (might be different color code on yours).

You can also hook a horn relay to this same signal wire, to beep in conjunction with the light flash. But you will need a diode between the Keyless unit/beeper and pin #6 to keep it from beeping when you turn the park lights on. Negative side of diode to pin 6, positive side to keyless unit and beeper.

DG