sunroof won't open

[Dwsewell]

I have a 1988 928 S4. I've been able to fix several issues with the car recently but I am still relatively new to the car.

The sunroof will not open. When I push the button on the center console, I hear some clicking in the area where the motor is but it's very faint and that is about it. I've read through the forums and have seen issues from the button itself (geez, the replacements are expensive. I know Porsche's are expensive in general to maintain but that'a lot of money for a button), the motor or that the sunroof could be stuck or off track.

Does anyone have any suggestions on the most common issues or the best order to begin to troubleshoot the issue?

I also have a problem with the sunroof motor cover hanging down it looks like one of the two small brackets that holds the cover up to the roof is broken. I haven't been able to locate anyone that sells that piece. Any suggestions?

[stepson]

Remove the sunroof motor cover and touch the sunroof opener button. Does the motor engage the sunroof transmission and spin the rubber connector between the two? Does that spinning rubber connector make the sunroof transmission turn?

That rubber piece is replaceable and can be purchased.

If the rubber connector DOES make the sunroof transmission turn even ever so slightly, but the sunroof doesn't move, your cables that make the sunroof move are probably gummed up. You can find a link to threads about removing your sunroof and cleaning and re-greasing those cables.

Good Luck!

[Dwsewell]

the rubber connect does move but it only seems to do it slightly if you push the close button. I cranked the sunroof open manually (started using the tool that comes with the car but then went to a large flathead because it was easier). I got it all the way opened and tried spraying some silicone in the areas I could get to just to check before I tore it apart. I was then able to close the sunroof with the button, but it would not open back up. Is this an issue with the button (closing part)? Seems like taking it off, cleaning the contacts and putting dialectric grease on would be the best first step. I'm reading the the buttons are very fragile. What's the best way to take them off without breaking them?

[stepson]

When you hit the button to close, does the motor run, turn the rubber connection, and consequently make the sunroof transmission move the sunroof? Just by looking while you are pushing the button could tell you what is happening or not happening.

[husker boxster]

If all you've done is spray lubricant on the track, you may have only lubricated the dirt. The sunroof needs to run freely in order to work. If yours is running under a load, that means something is holding it back. There's probably 30+ yrs of dirt on the tracks. Your best bet is to tear it apart, clean it, lube it, put it back together.

I just went thru this adventure with my recently purchased 87 S4. A friend emailed some pics from the service manuals on how to remove the sunroof. It's not too difficult. If you don't have access to the service manual, PM me your email addr and I'll fwd the email to you.

Besides being very dirty, mine had the passenger side cable broken. There's a pin that connects the cable to the sunroof. It was broken. I also found the sunroof trans was partially stripped (probably from me and others trying to run it while it was stuck). I replaced the trans as a last step (after cleaning and testing with the sunroof tool) and now everything is working as it should. If yours isn't working smoothly with the tool, there's something causing it to slow down or hang up. Best to investigate further before causing more damage. Parts are getting harder to find.

Here's a pic of the driver's and passenger's side cables.

[Dwsewell]

Originally Posted by stepson

When you hit the button to close, does the motor run, turn the rubber connection, and consequently make the sunroof transmission move the sunroof? Just by looking while you are pushing the button could tell you what is happening or not happening.

It is closing normally and the rubber part turns when you close. The rubber part does not move when you push open. Because it is working fine closing, that suggests to me it must be in the button? What do you think?

[Dwsewell]

Originally Posted by husker boxster

If all you've done is spray lubricant on the track, you may have only lubricated the dirt. The sunroof needs to run freely in order to work. If yours is running under a load, that means something is holding it back. There's probably 30+ yrs of dirt on the tracks. Your best bet is to tear it apart, clean it, lube it, put it back together.

I just went thru this adventure with my recently purchased 87 S4. A friend emailed some pics from the service manuals on how to remove the sunroof. It's not too difficult. If you don't have access to the service manual, PM me your email addr and I'll fwd the email to you.

Besides being very dirty, mine had the passenger side cable broken. There's a pin that connects the cable to the sunroof. It was broken. I also found the sunroof trans was partially stripped (probably from me and others trying to run it while it was stuck). I replaced the trans as a last step (after cleaning and testing with the sunroof tool) and now everything is working as it should. If yours isn't working smoothly with the tool, there's something causing it to slow down or hang up. Best to investigate further before causing more damage. Parts are getting harder to find.

Here's a pic of the driver's and passenger's side cables.

I'm sure you are right, after 32 years it is bound to be dirty. Mine seems to be closing fine, but not really doing anything at all when you push the open button. I'd like to figure out why it's only working one way before taking it apart and cleaning. It actually slides very smoothly when closing. Because the rubber piece moves when you press close (even when it is closed) and does nothing when you press open makes me think that it has to be somewhere in the button.

I would like to get the info from the service manual that you offered so I will PM you my address. Thank you!

[stepson]

Originally Posted by Dwsewell

It is closing normally and the rubber part turns when you close. The rubber part does not move when you push open. Because it is working fine closing, that suggests to me it must be in the button? What do you think?

I think that you would be correct to replace a switch that may be close to 40 years old. The switches are pretty cheap and relatively easy to replace.

Hint: I use a thin not thick blade to slide into the aft side of the switch to release the spring steel holder from the console. Generally the new switches do not come with the plastic connector. Find the connector for the sunroof (I have CRS and can't remember the color, but there is a red connector, a green one, and a yellow one), detach it from the harness and take a picture of the wires BEFORE you remove the wires to transfer them to the new switch wires. Once you remove the old switch wires from the plastic connector, you can slide the wires back through the console and out. Slide the new switch wires back into the console and after you are relatively happy with the wire placement, install the new wires into the old plastic connector. Not necessary but it can help with issues down the road.
Good Luck

[Mal81]

The switches are also easy to clean / fix. There are some posts about how to do it. Germans aren’t big on waste. You’ll find many parts on your car are repairable. Failing that, our Chinese friends are happy to sell you a new one on places like fleabay, but the quality may not be the same.

[Tim Boyer]

Check the relay and the fuse