Help Wanted! LF & RR Windows Inoperable - PeachParts Mercedes-Benz Forum

1985Az300DTurbo · #1 03-02-2007, 10:30 PM

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

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?

MBeige · #2 03-02-2007, 10:35 PM

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.

ray m · #3 03-02-2007, 10:37 PM

second that

vstech · #4 03-02-2007, 10:36 PM

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

TheDon · #5 03-02-2007, 10:39 PM

has to be the fuse

tangofox007 · #6 03-02-2007, 10:46 PM

Quote:

Originally Posted by TheDon

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.

Jeremy5848 · #7 03-03-2007, 01:56 AM

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.

1985Az300DTurbo · #8 03-03-2007, 10:19 AM

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

I don't suppose the Toyota people even have a forum like this do they?

tangofox007 · #9 03-03-2007, 10:23 AM

Quote:

Originally Posted by 1985Az300DTurbo

Is the rocker switch difficult to remove from the console? I would like to check it out before tearing into the door.

You can pry them out with a small screwdriver.

tangofox007 · #10 03-03-2007, 10:22 AM

Quote:

Originally Posted by Jeremy5848

Like the brake circuits, which are also diagonal opposites.

Are you sure about that?

Brian Carlton · #11 03-03-2007, 10:28 AM

Quote:

Originally Posted by tangofox007

Are you sure about that?

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

MarioCR · #12 03-05-2007, 01:17 AM

I have the wiring diagram for your car, but I can't post it because is too big, and if I resize it, you can't read the text. Let me know your e-mail, I will send it to you.

SD Blue · #13 03-05-2007, 11:25 PM

Or even better yet, go to the top of the page and click on "Buy Parts". That's what supports this forum where you found an answer.

tangofox007 · #14 03-05-2007, 11:44 PM

Quote:

Originally Posted by SD Blue

Or even better yet, go to the top of the page and click on "Buy Parts". That's what supports this forum where you found an answer.

Have you looked there for brass/copper fuses?

SD Blue · #15 03-06-2007, 11:31 AM

Well, I went to Buy Parts and the fuse kit has the MB logo on the package. That is what I ordered about 3 years ago and what I received was a container of tinned copper fuses with that same MB logo. Since then, no intermittent fuse problems. (Before that, I had intermittent ACC and windows.)