i just bought my first mercedes diesel a few weeks ago and it came with a full array of quirks and a list of projects. the one i am totally stuck on has to do with the power windows. i have searched the forums and haven't found a simular story. here it is...

the windows work fine for the first 2-3 minutes after starting the car. after that, they are stuck in that position for the duration of the trip. the sunroof works fine and never fails to respond to the switch. if i turn off the car, wait about 2 minutes, restart the car, then the windows work again. i have cleaned all the switches in the console with isopropyl and q-tips (they looked like a hobo had cleaned his ears after 2 years on the trains). any ideas? i did notice one of the wires for the front passenger switch was cracked and the copper a bit frayed, but it still had connection. i am gonna lube the windows when i get a chance, but i cannot imagine that this would the the culprit...

my rheostat is bunk as well...gonna try the solder trick today.

my steering has slop to the right (may be both directions, but the wheel "grabs" to the left when the wheel is level, to the right it "grabs" at about 2 inches) i am thinking of replaceing the steering dampener before adjusting the steering gear box. i looked under the car as a friend turned the wheel. the rods and such move about 2 inches before the wheels start to move. could this be the dampener or maybe something else? there seems to be no difference in movement between the steering shaft and the drop arm from the steering box (forgive me for not giving the correct terminology). suggestions on what to check to properly diagnose would be much appreciated.

this car is also set up to run WVO. the engine is absolutely filthy, covered with grease and grime. i would like to clean it up a bit, any suggestions as to what i should use and how to go about it?

I am digging this car, and i am especially digging this website. your posts have already helped me fix many of the small issues with this car. thanks.

Howdy and welcome.
Not sure about the windows, in my SD they work after a while, but not at first.
Inspect the damper closely, if you mark the steering adjust bolt you can put it back there, you may want to try that first, an easy adjustment.
Some folks will mention to take it to a car wash, open the hood, spray a degreaser, wait a bit, agitate with an old brush, and rinse off. I'll suggest being very careful doing this, as you may knock something loose/off or get water in the intake.
Post pics when you can.

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83 SD

84 CD

what needs to be protected from getting wet in the engine compartment. i'd assume that the alternator needs to be covered. what other componets should be covered?

Below is a pic of my switch. In the upper left corner you see one of the contact points is burned. Just putting Alcohol on a Q-tip will not cure that. I scraped it gently with a small knife blade and sanded it a little with some 220 grit emery paper. 2 other contacts in that switch needed the same treatment.

When I got my Car It was oily and grimey all the way back to the end of the tansmission (mostly due to a leaking Valve Cover Gasket).
I went to the local discount store (1 dollar + store) and got cans of Spray Engine Degreaser. It too 4 applications; after which I was able to tell that it was the Valve Cover Gasket that was leaking.
Since then some perodic spraydowns with something like Simple Green are enough to keep the build up from forming with the other small leaks I have.

More Window stuff. Along with the switch problem I pulled the Door Panels off the Rear Doors and found that the Window Regular Mounting Plats in bot doors were severly warped.
The warping had caused the Regulator Gear Teeth to wear an an angle to the point where the did not work or barely worked.
I have a thread
http://www.peachparts.com/shopforum/showthread.php?t=254722&highlight=Extreme

However, I have had no problems with my front windows.

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84 300D, 82 Volvo 244Gl Diesel

We call the arm that attaches to the Steering Box a Pitman Arm.
If your wheel moves and the Pitman Arm is not moving there is and adjusting Socket head secrew/nut combination on top of the Steering Box. You can open the hood and look down and see it there.
Ounce the nut is loose turning the Socket Head Screw anti/ counter clockwise tightens up the steering.
If you turn the wheel and the Pitman Arm moves with the Wheel but the other Steering parts do not move and turn the wheels; those parts are worn.
I removed the Steering damper from my Car and had no negative effect at all; so it is not a cause of your steering problem.

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84 300D, 82 Volvo 244Gl Diesel

ok. took out the rheostat. it was covered in oil. probably from the oil gauge leaking at some point. i cleaned it out and soldered a wire across the connections. too bright to see if it worked yet, but will probably be keeping the flashlight in the car for a while just in case.

i will try the adjusting screw.

i did a search on the forum for engine clean...should have done that first. i like the idea of going to the car wash to clean it. the car is already dropping oil on my apartments cement. dont want to leave stains. will pressure washing it remove the stains from the cement, or do i need a cleaner/solvent?

will redo the switches, just in case. the thing about the windows is after a few minutes of driving, the windows have no response. no noise, nothing. but then after sitting for a few minutes with the engine off, they work again. i will open up the doors soon and check on their condition.

The alt is low and prone to getting wet from driving in the rain, but not pressurized. Were you to knock off a vac connection and get water in a line, not sure what would be the result.
The allen adjust screw may turn when you loosen the lock nut, turn it counter clockwise to tighten, too far and you won't be able to steer lock to lock.

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83 SD

84 CD

Since the power windows do not operate with the key off. Chances are pretty good a power up relay is turned on when you turn the keyswitch on.

This relay may be flakey so find it and change/substitute/ fix it. There are two separate fuses for the window circuits. The only item that would process both of these power sources for the separate windows has to be that relay. It is not the child rear window security switch as that does not effect the front windows. The keyswitch acc portion could be opening up after three minutes. Other things would be effected I suspect in that senario.
The relay is a prime suspect at least in my mind. Or very high on the probability list.

I agree with Barry, I believe you have a relay problem. It sounds like something is drawing a bit more current than it should, and since the windows have current to them at all times, one of your window motors could have some faulty brushes or a armature shorting to the field. I would unhook one of the motors (assuming both back windows work), and see if that corrects the problem, if not try other side to isolate your problem. Congrats on purchasing the most fun car on the planet to work on! Get good at removing your door panel trim. Where the door panel attaches on the door, under the 1/4 window part, are two clips that usually come off with the panel, remount them on the door metal underneath the weatherstrip first, a lot easier putting the panel back on. Good luck!

excellent. does anyone know where the relay/s are located? i looked in the haynes manual and they indicate a window relay, but it does not say where this is. also, any pics or links to parts suppliers with pic would greatly help.

They do sell driveway cleaner in a pump type spray bottle. Needs to be washed off with water afterwards.
I have not seen them for awhile but they used to sell Galvanized Steel Drip pans with about a 1/2 inch lip around them about 4 feet by 3 feet wide to put under a car to catch the drips.
You would have to decide if that is something that someone would steal in your at your Apt parking spot.

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84 300D, 82 Volvo 244Gl Diesel

The Power Window Relay is behind the Instrument Cluster. Behind what you already accessed to do the Soldering.
See pic.

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84 300D, 82 Volvo 244Gl Diesel

I would tend to monitor the wires feeding that relay to see what drops out after three minutes or so. What bothers me is there is no current flow other than what is required to keep the relay closed with the ignition on.

You want to make sure that voltage is still present after three minutes if possible. In otherwords troubleshoot the relay to verify it is bad. You do own a digital meter? If not aquire one as you will find many uses for it over the years.

Also inspect the relay prongs for oxidation as expansion with the modest current flow could cause an old connection to open. This problem is probably temperature related as when you shut the car down for a few minutes the windows start working again apparently.

Same relay in a gas car of the same series. May in fact be a very common part in many series. The same part number could occur on other relays in the car maybe. If so you can temporarily borrow one for the test.

I know little of mercedes relay usage policies. Salvage yard item depending on availability of wrecks in your area as well. In fact if you can aquire one cheap enough (close to free) just make sure the contacts and receptical contacts are clean and plug it in. If windows are still operational after awhile you have it.

very nice. i will hit up the salvage yards to find that relay. i have a multi meter and will check the relay in the next few days.

i have cardboard down currently under the car. the area i live at is a bit sketchy...lots of shade tree mechanics on the weekends, so i am gonna stick with the cardboard for the drips. i am planning on replacing the fuel hoses, since some are cracking and the bottom of the engine is covered with grease/oil. my guess is that one of the wvo lines are leaking. i am thinking of running a few tanks of biodiesel thru the engine to give it a cleaning, since i have heard it is a good solvent. what do y'all think of this? is it worth it? should i bother? i have seen products on dieselgiant that you ad to the engine directly. i already have extra fuel filters on hand to exchange when the old ones clog (not old, they were changed in the last year).

i also am thinking of taking 'er in for a tune up/check up. going in for knee surgery in a month or so and want it ship-shape for my lady to drive me around. anyone know of a good bay area mechanic to try? is there a mechanic referral forum on this site?

i knocked loose one of the vacuum hoses off the ignition while working on the rheostat today...this website totally saved me. i cleaned and reinstalled the hoses and now the 300 "diesels" less when i shut it off. beauty.

just found the shop reference link. nice.