A Stumper
 

Here's one that may even stump the Master Mechanics:scholar: : On my '84 300D, my sunroof only works when it's hot out. I'd say if the outside temp is above 80f:sunny: , the sunroof works fine, but below that, it doesn't move, even if I try and nudge it. I replaced the switch (didn't help), but I have yet to remove the motor. Could the heat actually have an effect on the motor? I thought it may need greased, but like I said, it won't budge, even if I try to help it along. I'm open to any words of wisdom. Thanks,

Ike :dancefool (there's a bunch of those little faces, they could really get irritating if somebody had too much time on there hands)

do you use the mercedes benz slide rail grease your are supposed to use? do you hear the whir of the motor in the trunk?

No, I never greased it yet. I looked for it once, but I couldn't find any. Do you think that is the culprit.

Ike

I believe there is a therm resistor of some sort that prevents the motor from overheating, perhaps it is working oppositely?

Is the clutch between the motor and the cable slipping?

My 300SD works very poorly when cold. Really great when warm to hot outside.
I am convinced it is grease in the tube binding the cable.

When the grease is warm it allows easy travel.
I completely cleaned the slides in mine.

My plan is to remove the cable (from the interior side) and flush the tube through to the trunk. Then relube the cable.

There are a few threads that talk about this.

I don't think the clutch is slipping, and I need to get my wife to push the button so I can hear if the motor is whirring.

I was talking to my sister, and mentioned this problem in idle conversation, she asked if it had a weather sensor. She's a great cook though

From someone who now has tried to fix a stuck sunroof AMHIK....and now has to ride with the headliner removed and slide the SR manually by hand withthe cable disconnected from the gears;
LEAVE IT ALONE!!!!
Just be happy it works when it's warm out.
I followed ************** sunroof manual to the tee, & cleaned regeased replaced worn parts...and it is worse now than when it wan't working.

Turns out if I just replaced a worn fiber gear and left the guide tube, cable and rails as they were I would be enjoying a fine electric sunroof.

Don't count out the switch. The MB rocker style switches get worn and with higher temps the contacts separate too far to make contact.
Should be able to hear the electic motor straining though, if not check that switch out.

Sometimes I really hate my manual sunroof, have to pull down the handle, turn it, and then slide the roof back to open....and then I have to close it by hand too!

Sometimes I really love it (like after reading your post).

Thanks for the input, I did replace the rocker switch, but I have yet to listen closely to the motor. Maybe I'll take the above advise and be happy when it works.