Central locking issue...

Drumster · Post by **Drumster** » Fri Jul 21, 2017 8:18 am

Hi folks. My '94 L400 has about 117 K now and is running fine... except the central locking is no longer working for front doors. Works normally on other doors but not front. So it seems the solenoids or whatever makes the motion, are kaput. As both left & right are affected it seems to me there's possibly an issue with wiring, rather than the actual solenoids. I'm far from being an expert... can anyone shed light on what might be the problem?
Thanks!

Drumster · Post by **Drumster** » Sun Aug 20, 2017 5:25 pm

I need to amend this... earlier observations were incorrect. Only the passenge fron door is acting up and only as gfar as locking. It will open with remote or withe ignition key on driver's side door, usually, but will not lock with remote or with central locking via key. So I'm guessing there's a solenoid i the door for that purpose and that it's not working in "lock" direction... Hmm....

Davidor · Post by **Davidor** » Sun Aug 20, 2017 9:10 pm

I had similar issue with my van... the passenger side was working but would be slower than the rest of the doors and eventually it just stopped. The downside is the lock actuator for the driver and passenger doors looks to be a whole unit with the latch mechanism itself. I had the door panels open, took out the bolts holding it in but then the window slides got in the way of fully removing it and that's where I decided it was a project for another time... You may need to take the door handle off and perhaps there are more screws there to take the thing apart.

From what I have gathered is that the door lock actuators (at least for the sliding door as I did manage to replace that one in my van) use a 12+ (or -, I'm not exactly sure which one) signal to lock the door and then the reverse polarity to unlock the door. If the weather stays nice and I decide to open up my door panels again I'll let you know what I find.

If you get eager and beat me too it, the locking signals are sent on pin 3 and pin 4 (the bottom two) of the 4 pin connector attached to the solenoid. They should be the blue wires with a black stripe...

Drumster · Post by **Drumster** » Thu Aug 24, 2017 3:16 pm

Thanks for the reply Davidor!
I don't know if it's 100% accurate but your +/- interpretation makes sense to me.
If so, it seems to me there should be something within the passenger door mechanism itself that's identifiable and repairable too, hopefully. The prospect of opening up that can of worms is a bit daunting though so not too that I'll tear into it before you! Will let you know if I do though.

Can you provide a link to how to pull the door panels out etc? If I get into it I might even replace the speakers!

Cheers!

Davidor · Post by **Davidor** » Sun Aug 27, 2017 9:53 pm

I don't have a link for the door panels but I can walk you through the personal experience...

There will be 2 screws accessible from the door panel, the first one in the little cup you use to close the door and the other behind the door handle. After you take the one behind the door handle out, the little plastic trim piece will come out, there is one more little screw behind this that will need to come out that goes through into the plastic behind the metal plate. The big screw in the door closing compartment (I'm sure there is a better name for it), once you get it out the whole plastic piece with the window switch should lift back and out (there is a tab on the front). Disconnect the wiring harness for the window switch. From here everything is little plastic clips, if you have the tool for them it's like a slotted screw driver (I got mine from princess auto a very long time ago) or a normal flat blade can work too. Pry the door panel off until the first clips start to pop, I usually start at the bottom corner and after you can get your fingers in there they come out pretty easily. After this everything else is fairly self explanatory.

I've yet to see a set of stock mitsubishi speakers inside any of the doors I've opened up but I have heard the stock ones have a weird bolt pattern. I had to make mounting plates for mine but afterwards regular 6.5" speakers fit nicely.

Drumster · Post by **Drumster** » Mon Aug 28, 2017 4:27 pm

Thanks Davidor. When I get around to checking it out I may decide to finally upgrade the speakers too!
Cheers!

Drumster · Post by **Drumster** » Sun Sep 10, 2017 11:06 pm

Well, I'm not sure how to explain this but my central locking is fine again and I did nothing. I think possibly the fact that van had sat previously for some time and battery grew weak might be a factor. Since taking it on few highway runs down to Washington it's all back to normal so the battery maybe just needed a bit of alternator inspiration!.