Help Wanted! LF & RR Windows Inoperable
 

My driver's window is stuck in the open position following a fairly typical commute home earlier this week. The right rear window is also non operating in the closed position. I checked my CD ROM Benz manual and I don't have a power window elect schematic :mad: I checked the fuse box and I have power to the "b" circuit which is labeled for power windows. It seems strange that both windows on the same circuit would fail at the same time. Any suggestions on where to begin? :confused:

It's one of the fuses I don't remember which one but your car's symptoms is a classic sign of the window fuse. Wiggle them and make sure you've got good contact, it should start working again. If not, replace the fuses. ;)

put in a new fuse to be SURE it's not that.
you can CAREFULLY remove the door panel dieselgiant.com has a nice DIY pictorial on procedure for this.
and you can apply power to the screw leads that power the motor directly to verify it's operation.
john

second that

has to be the fuse

If two windows fail for any reason, there is a one in three chance that they will be on the same fuse.

Mercedes wired the windows so that diagonally opposite ones work from the same fuse. This is probably so that, even if one fuse blows, you can still get one on each side, and one front, one rear, to work.

According to the diagram on the inside of the fuse box cover on my '85 300DT, LF & RR are on fuse "b" and RF & LR are on fuse "a." If even replacing the fuses with new ones doesn't help then you may have a bad switch, relay, or wiring. However, the fuse is always the first to check. Remember the advice previously given: even if you have power at the fuse according to your test meter, replace the fuse with a new one.

Using my DVM, I checked the voltage at the fuse block and I have power on the "b" circuit side of the fuse and the fuse looks fine, visually, so (at least on the surface) it doesn't seem to be the fuse. Unfortunately, I don't have a wiring schematic of the cirucuit since it wasn't included with the CD manual I purchased on the web. I will do the wiggle test and fuse replacement this morning, and go from there. Is the rocker switch difficult to remove from the console? I would like to check it out before tearing into the door.

Thanks to each of you in this forum for all the good advice I recieve :) When I purchased this Benz a year ago, I knew it would involve some tinkering, and this forum is the perfect solution for us DIY's :cool: I don't suppose the Toyota people even have a forum like this do they?

Are you sure about that?

You can pry them out with a small screwdriver.

I'm sure that it's incorrect. I edited the post.

I would rather just remove the wood panel and pop them from the underside so to not mess up the finish on the wood.

Tango. I'm sure about the DVM readings. Let me verify. The power bus seems to be in the center of the fuse block. I checked the opposite side of the fuse for voltage. I'm reading -13.67 volts. This is a "no load" test, so I should perform this while trying to operate the windows, just be sure, which I haven't done yet. Thanks

clean fuse contacts
 

Try this simple fix Before you go pulling switches...
Use some emory or crocus cloth (or superfine sandpaper) to gently but thouroughly clean and polish the fuseholder contacts and the ends of each fuse. Then try it again.

Pull the LH console switch and see if you are getting power at pin 3 (front switch connector).

On the RH rear door switch, check for power to pin 3 & 7.

Also, on the LH front window, does the motor run when "Down" is selected on the switch?