'94 W124 E320 RCL issue

[MotardMan]

All,

Despite the dealer changing the fob batteries, the car still will not lock or unlock from the drivers door, though the fob works fine via the boot mounted sensor.

As these RCL components tend to be very pricey, which oder would you guys go about replacing things to fix my issue? LED's? RCL brain?

 

[Bolide]

If the RCL works via one sensor and not another then logically one sensor is faulty. If you can trace the RCL cable through the tailgate and stick a meter or scope on it you should see the voltage / signal present when the sensor is activated. Test for the same on the driver's door. If it's not present suspect the wiring and the sensor

I imagine you could run a cable from the rear sensor to the connection for the front sensor (and vice versa) to test the cabling & sensors

The sensor is probably nothing more than an IR detector with a signal conditioning pulse generator to talk to the brain. If it's kaput, and the detector is separate to the rest of the unit, I'd try a new detector from a TV shop. It might work

Nick Froome
www.w124.co.uk

 

[MotardMan]

Many thanks Nick, great advice. I'll get the door disassembled and check out the wiring and connectors, if they check out OK, I'll take your advice on the receiver.

I will of course, post the findings in this thread. We pick up the car on Saturday, so expect some news later next week sometime...

 

[Bolide]

All the connections to the tailgate go via a curved screw connector block in the headlining behind one of the hinges. I'd start there with a meter or scope and locate the cable. When you know the colour you can find the same cable in the drivers door

Nick Froome
www.w124.co.uk

 

[MotardMan]

I'm guessing the theory is the same for the Coupe, which is the car I have the issue with?

 

[television]

I'm guessing the theory is the same for the Coupe, which is the car I have the issue with?

Nick is correct in the procedure for checking the signals and I scope them too.
often it is just a dry solder joint on the sensor due to the vibration in the closing of the door

 

[MotardMan]

Nick is correct in the procedure for checking the signals and I scope them too.
often it is just a dry solder joint on the sensor due to the vibration in the closing of the door

Brilliant. I assume these units can be disassembled then? I cannot wait to get the car home and start fixing these things. I'm handy with the soldering iron, so if it proves repairable, I can do it. Gotta be worth a try for a few hours manual labour right? At least my time is free to me.....

Jim

 

[television]

Brilliant. I assume these units can be disassembled then? I cannot wait to get the car home and start fixing these things. I'm handy with the soldering iron, so if it proves repairable, I can do it. Gotta be worth a try for a few hours manual labour right? At least my time is free to me.....

Jim

When you re solder, just make sure that the joints are bright and shiny, you must add solder (cored)

There is no way to measure the sensors cold on a meter there should be 3 legs on them the + - and signal, voltage wise they have 5v on the plus and around 3v on the signal pin

 

[MotardMan]

Just a quick update for you. I have managed to locate a used RCL receiver and door handle complete, as soon as the "transaction" is done and I have the parts in my hand, I'll swap the bits out and let you all have the result. I'll then strip the faulty unit down and try to post up the results with some pics using the advice above for repair.

 

[MotardMan]

Just a quick update. The original seller has let me down, do any of you guyds have a part number for the unit that lives inside the door and receives the signal from the fob? I looked on the Russian site but cannot seem to locate the correct part........

VIN is: WDB1240522C017092

Thanks in ADVANCE

 

[MotardMan]

Bounce!


Nobody?