When I took My Counsel Window Switches apart they were beyond any sort of chemical cleaner. I used a small Pocket Knife Blade to scrape the burned/oxidized part off of the Contact Points.

Also keep Brake Cleaner away from the Switch as it softens the Plastic.

In the picture the contact that is circled has not been scraped. The 2 lower ones have been scraped but notice the craters on them.

There is other Contacts on 2 the Rockers that are not shown in the Picture and there is other parts not shown in the Picture.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

If in doubt, brown wires are always ground.

On my '85 300d:

- rear windows worked until recently from either center console or door switches. Few months ago I noticed left rear worked when it felt like, from either switch.

- now neither side works from the door switches.

- right side works from console, left does not.

- left side: getting power to socket #7 with key on.
- right side: getting power to sockets 3 and 7, key on.

- have tried three switches on left door window motor, both spade connectors on the motor stay hot all the time regardless of switch position. I have one of the soldered-on-connectors motors.

UPDATE: turns out my multimeter has issues. Borrowed one, looks like I have no ground at the brown wire socket on the left door.

Does the ground go through the switch on the console? (I am Forrest Gump on electrics.)

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

The chassis ground wire connects to pin 4 of both console switches. There is a ground conductor within the switch that connects to pin 4. Internally, there is a connection from this internal conductor to the safety switch and from there to pin 5. It is hard to describe in words, but You can see this in the diagram I posted for the 85. If the safety switch is open, then there is no ground for the rear motor and the rear window cannot be opened.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

The safety switch only affects the operation of the rear windows from the rear door switches.
The safety switch has no affect on the console switch operation for any windows.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Finally got some time today to follow-up with some of the suggestions - I really appreciate the help and the ideas!

Let me ask a clarifying question: There appears to be only one ground wire per left AND right side switch - not one for each of the front and front rear switches - correct? if so, I have have a good ground on each side. I next checked the resistance of each wire from socket to screw on the door and each check out - no broken wires - resistance was zero.

I didn't connect 12v to sockets to see if I could operate the window that way, but I might try tomorrow - although, with 0 resistance from socket to door, I think my switch is the trouble - at least that's what I'm hoping. I brought the switch home and cleaned/scraped it (my son and his wife have been using the car). I'll install tomorrow and see what happens.

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

That is some good progress!

I believe there is just one ground point for both switches (g102). If you look at the last wiring diagram I posted, you will see that the wire from pin 4 of each switch leads to a junction c107. The wire from c107 terminates at G102 which would be a chassis ground. c107 appears to have pin or socket numbers. Perhaps it is a connector? Anyone located it.

From what I recall, it is not easy to follow these wires, because they are partly enclosed in a harness. But it appears you have confirmed that you have a good ground connection from the switch plugs and that wiring to door is likely good.

It does seem that everything points back to the switch.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I think the confusion in suggestions for trouble shooting power window problems is using the term "ground" for measurement of voltages. You should never use "ground" for a probe of the meter or a test light. Always measure across the motor winding to check if power is present, i.e. do not use GROUND!. If you do, you will get very confused from the results.

Whenever I have power window problems, it always ended up being either the fuses weren't making contact or the switches were not making contact because they were full of gunk. dust and hair. The switches come apart easily for cleaning. As long as the contacts are not physically burned away, they can be cleaned and the switches will be good as new.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

If you measure across the motor lead wires with a perfectly good car, you should get zero volts. That is confusing for a start. But if you measure each side to GROUND, then you will get 12V which is also correct.

But you are right, if you check across motor leads with switch in up (or down) position you should see +/- 12V. If you do and the motor is good, it will run!

But if it doesn't run, that's where the troubleshooting comes in and that is the problem Ryan has. Making sure switches have a good ground is a first step (which he has done).

Hopefully you are right and he can clean up his existing switch.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Well, maybe I was not being clear, but you must activate the window switch while measuring across the motor. I thought that's common sense? The window switches should not be grounded. The switch has to reverse the polarity of the voltage to the motor for it to go up and down. If the switch is grounded, it cannot reverse polarity and will blow the fuse.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Have you looked at the (post #26) schematic? What is the purpose of terminal 4 on the front window switches?

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

To be more precise, the switch wiring to the motor should never be grounded is what I meant to say.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

For all practical purposes, that is precisely what happens when the window switch is actuated: one wire to the motor disconnected from battery positive and switched to ground.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Just stop and listen, you're confused.

The BOTH leads to the motor have 12V+ when the switch is at rest, as the OP verified by measuring each lead vs the body. If you push the button up or down, one side or the other will be grounded through the switch in the center console. What seems to be happening here is that the leads are never connected to ground, which is almost always a switch problem. If not the switch itself, then the ground connection to the console switch is bad. The switch can't be tested by exchanging left and right, and while the wiring could be tested by jumping the connector, differences in numbering sequence make me hesitant to suggest that.

Ok, I am confused. I stand corrected. I'll go hide in the corner now.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked