karthick

I have a 1993 LS400. I recently acquired it. The drivers side Front Master window switch was dead. I found that I could operate the driver's window but I couldnt operate the other three windows. The door locks worked fine. It seems that a ton of people with 1st Gen LS400s have this issue so I was wondering if the switch could be repaired.

I dont have pictures in this thread and thats because I didnt know if what I was doing was going to work or not.

I got myself a can of CRC Electronics cleaner.
http://www.acehardware.com/product/i...ductId=1451535

I poppped the switch (Front drivers side master switch) of using a fine flathead screwdriver. I popped it off using one of the threads on www.lexls.com as a reference. I then unhooked the connector from the switch (Causing quite a bit of pain in my fingers). I then disassembled the switch.
At this point, I know that pictures are essential but when I was doing this I didnt know if it was going to work or not.

Disassembly instructions
The switch essentially has 3 parts.
1. The top plate (Wood trim on top and plastic underneath)
2. The switch mount plate (making the name up of course) into which all the switches fit. This is black plastic.
3 . The Bottom white wiring and contacts holder. This is the part that holds all the electrical contacts (Its quite amazing when open). This is white plastic.

Part2 and Part3 is actually a subassembly that you unscrew from the top plate. This is done by removing 3 screws (They are obvious once you have the switch out). You need a medium-small size phillips screwdriver. Once you remove these 3 screws you can separate the top-plate from the switch subassembly.

Part-2 is connected to part-3 using 5 black screws (or is it 6). These screws are on the black side of the subassembly. One screw in the well of each window switch and one at the end. Remove these screws slowly and you will find that the subassembly is gently spring loaded so the two parts (Part2 and Part3) will seperate slowly.. There are 5-tiny springs mounted on tiny plastic shafts on the the inside of Part 3. These springs will fall out once you remove the 5 black screws. Save these springs, you need them to reassemble.

Now Part2 and Part3 are seperate. Part2 (Black plastic) holds all the switches. and Part3 holds all the contacts. Just a complex maze of springy copper strips (not wires). Some of the contacts looked hazy and some of them had some kind of oxidation on them so I used the CRC Electronics cleaner and liberally sprayed them down and used a q-tip to gently wipe them after spraying. I did one contact area at a time (there is one area for each switch). I waited for it to dry and repeated the process. I let it sit for about 20 minutes after which it seemed like it was dry.

I then reassembled the contacts with the switches (part2 and part3) (Dont forget the tiny springs). and screwed the subassembly back to the top plate.
I put the switch assembly back in the door after connecting the wires .

Switched on the ignition and tried the window switches.. They work!! Voila..

There could be several reasons why the window switches go bad but my guess is most of them have bad contacts. Cleaning them as I did could fix your problem. The disassembly is pretty simple. Takes 5 minutes. Just a bunch of phillips screws..

About the other door switches, I opened up the rear window switches but the contacts are not exposed like the front master switch. However you can spray the Cleaner into a couple of holes in the switches. This might work for them too but Since you cant get a q-tip in there, the results might vary.

Happy Fixing

KA8

iTrader: (1)

Wow exact problem I'm having with my LS. Thanks

timmy0tool

iTrader: (7)

yes sir, a common issue with older cars that see extreme temps and humidity. good job on the fix!

jerryparks

iTrader: (1)

Mine are bad on my '9LS. Cant operate the pass side window with the switches. I'll try the repair fix later.

Dubbayoo

I ended up replacing the entire switch plate. It was pretty pricey.