Delica Canada | Mitsubishi Van Club

My L400's passenger-side power window stopped working a couple of days ago. Neither the passenger or driver's side controls work, so I suspect the problem is the motor. But I'm trying to confirm before buying one.

Getting the interior door panel off was lots of fun. Seriously, I actually enjoyed futzing with it. With the panel and vapour barrier off, I got out my voltmeter and tried to confirm that current was getting to the motor. I get nothing from the red and green wires going to the motor. I am able to confirm power on some of the wires going to the switch, but nothing going to the motor.

This is all new to me. It's fun and all, but I've just about scratched a hole in my head. Advice?

Any disruption of the circuit renders it useless from either switch so it isn't necessarily the motor.

Could also be one of the switches itself (not that likely) or a break in a wire somewhere (very likely...most common spot for a busted wire being in the bundle of wires passing from body to door since they get moved around a lot.).

The wires on my Vanagons power window circuit broke multiple different times in multiple different places. Might not be the best method to follow for the L400 but here is how I traced the problems in my VW. I was able to confirm the motor was good by disconnecting it from the window regulator and hitting it directly with power. To track down what wire was broken I used the multimeter to check continuity of each wire in the circuit.

The worst thing is when a wire has broken but in the process of fidling with it, it gains contact again and looks like the continuity is ok leaving you going wtf...I found wiggling the wires a bit while checking would help prevent these false positives.

I would also suggest if it is a broken wire, if possible, run new wire from A to B instead of patching the old wire. The old wire is likely brittle with age and will break again somewhere else at some unopportune time.

Hopefully someone will post with a specific L400 power window troubleshooting procedure to cut down the guesswork. If not I hope some of these ideas help you out. Good luck.

Silly question, but have you checked all of your fuses?

tonydca wrote:Silly question, but have you checked all of your fuses?

Good question.

The driver's side window works fine. According to the fuse-box diagram available for download here, there is a single fuse for both power windows. So my assumption was that the fuse wasn't the issue.

But I should check if reality (the actual fusebox) matches the diagram.

psilosin wrote:[...]

Could also be one of the switches itself (not that likely) or a break in a wire somewhere (very likely...most common spot for a busted wire being in the bundle of wires passing from body to door since they get moved around a lot.).

If it were a switch, wouldn't it have to be both of the switches?

I'm with you on it likely being a broken wire.

So to test the motor like you suggest, could I just take a little 12V battery I have sitting around and hook it up to the window motor? Or would that be stupid? Automotive electrical is pretty new to me (obviously).

Good point about just testing continuity of the wires. Much simpler than looking for a voltage change based on the switch position.