Diagnosing Sunroof Problems
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From: Northwest
Diagnosing Sunroof Problems
Has anyone worked out a simple strategy for testing sunroofs that don't function to isolate whether the problem is the switch, the motor, or something else? Mine worked fine when I bought the car but, of course, now that the car is in my garage, the moonroof just sits there and quietly laughs at me. 
Harvey
Harvey
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From: Jersey Shore, USA
Harvey,
This isn't specific to the sunroof, but:
I diagnosed an issue with the seat switch (but still haven't fixed it) by watching the volt meter on the dash with the key on.
If you push the switch and the volt meter ticks down, then the switch is OK and it's applying voltage to the motor, but the motor isn't running for some reason (jammed?). If the volt meter doesn't twitch, then I would suspect an electrical problem because either the switch isn't making contact, or the wiring isn't applying any voltage to the motor, since it's not drawing any power.
From there you can decide what to take apart.
This isn't specific to the sunroof, but:
I diagnosed an issue with the seat switch (but still haven't fixed it) by watching the volt meter on the dash with the key on.
If you push the switch and the volt meter ticks down, then the switch is OK and it's applying voltage to the motor, but the motor isn't running for some reason (jammed?). If the volt meter doesn't twitch, then I would suspect an electrical problem because either the switch isn't making contact, or the wiring isn't applying any voltage to the motor, since it's not drawing any power.
From there you can decide what to take apart.
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From: Porterville, Ca.
I have pulled the cover and dropped the motor/trans and tried switch then. This only shows whether switch works though, not if motor is weak or trans bad. What really helped mine was removing cables and cleaning the guide tubes. It is amazing how much gunk and old grease came out. When clean I used white lithium to re-grease cables and installed.
If motor is working then trans is next. You can open this carefully (it is pot metal and crimped) and clean/regrease also.
If motor is good but switch not working then disassemble switch and clean contacts (probably should do this one first)
If motor is working then trans is next. You can open this carefully (it is pot metal and crimped) and clean/regrease also.
If motor is good but switch not working then disassemble switch and clean contacts (probably should do this one first)
Racer
Joined: Jan 2007
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From: westport, ct
are both directions of the switch inoperative? on mine sometimes the back part (sunroof opening doesn't engage) but when I depress the front part I hear the motor briefly. if so then the switch or the back contact is not good.
also trying isolating pressure on differenrt parts of the sunroof open part. with mine I have to isolate pressue on the left side about 2/3 rds back. I can usually get it open that way. I spayed some electrical contact cleaner on it first.
seems that's the first place to look, especially it worked when you tested it. same kind of thing happened to me.
also trying isolating pressure on differenrt parts of the sunroof open part. with mine I have to isolate pressue on the left side about 2/3 rds back. I can usually get it open that way. I spayed some electrical contact cleaner on it first.
seems that's the first place to look, especially it worked when you tested it. same kind of thing happened to me.
Racer
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From: North Las Vegas
Another problem area is the to hindges that the front guide bar attaches to. Only problem is you have to get the roof partially open first to get the roof liner out. You may need to get out the old hand crank! These hindges allow the front of the roof to pivot so the back will drop when opening. Did my rebuild & did not address these hindges & the roof tried but would not budge! Had to spray them & work them till good and loose, then all was nice!! Naturally, this is after you have all the eletricals in working order.
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From: Manchester,NH
Depending on year, wire color and fuse # are different. This is a basic test after making sure fuse is good and you have the wiring diagram.
If sunroof is inop.
-Disconnect motor and connect a test light in series on harness connector. If wiring and switch are good, light will come on with switch open or close. Problem is motor.
- If light did not come on, check switch for power and ground. Repair if required.
- Two wires at switch go to the motor. Connect these wires with test light, like a jumper. If light comes on open or close, problem is in wiring to motor. No light, bad switch.
If sunroof is inop.
-Disconnect motor and connect a test light in series on harness connector. If wiring and switch are good, light will come on with switch open or close. Problem is motor.
- If light did not come on, check switch for power and ground. Repair if required.
- Two wires at switch go to the motor. Connect these wires with test light, like a jumper. If light comes on open or close, problem is in wiring to motor. No light, bad switch.
Last edited by ZEUS+; Mar 31, 2007 at 12:46 AM.
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From: SF Bay Area
Harvey,
If your quick fix does not work then here is a more complete sun roof reference.
http://www.kondratyev.com/porsche/te...or/sunroof.htm
In most cases I have seen there is rarely anything wrong with the components. The switches get dirty and can be cleaned with DeOxIt and the tracks and cables get dirty and need to be cleaned and relubricated. It takes about 3 hours to completely disassemble the unit, clean everything and put it back together. After the sunroof will function like it was new.
Dan the Pod Guy
If your quick fix does not work then here is a more complete sun roof reference.
http://www.kondratyev.com/porsche/te...or/sunroof.htm
In most cases I have seen there is rarely anything wrong with the components. The switches get dirty and can be cleaned with DeOxIt and the tracks and cables get dirty and need to be cleaned and relubricated. It takes about 3 hours to completely disassemble the unit, clean everything and put it back together. After the sunroof will function like it was new.
Dan the Pod Guy
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From: Franklin, TN
You're aware that the sunroof can be manually closed with the supplied crank? I'm guessing you know this, but I started to wonder if your roof was stuck open.
Excellent suggestions here.
Excellent suggestions here.
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The S4's been sitting on blocks in my garage for about 4 months while I work to make up for past things the PO didn't stay on top of. Passenger window also is intermittent and runs slow so I'm thinking the stuff you guys mentioned have just compounded while it's been sitting Drove it yesterday the first time since complete the Tbelt/wp/rollers etc. refresh and it runs like the blazes so I just need to work on the little stuff ...sunroof....window...remove window tint...clean all grounds...put interior pieces I removed for R&R back in, put in new seat switch, repair some rubber stuff, pull underfender shields and check everything, replace all dash bulbs, etc. Runs like it should though...I'm pleased with the purchase but already wishing I'd held out for sport seats and LSD. Also, there are some pod cracks I need to deal with...just haven't decided how much $$ I want to throw into this car. I may make it my daily driver.
Like on many new purchases, there are a veriety of things that need to be tweaked. Thanks, guys, for all your informed help.
I will say this though, for a low mileage car, Arizona heat has not been real easy on some parts of it. I'm fixing all that. My '85S has always been garaged and has lived in the temerate climate of the Northwest and seems to have faired a bit better. The person who drove the 88S drove it to work and parked it outside. While the NW has moisture, and Arizona doesn't, there are no signs of salt damage ever and most looks to be near new in shape. Part by part, I'll get it.
Harvey
Like on many new purchases, there are a veriety of things that need to be tweaked. Thanks, guys, for all your informed help.
I will say this though, for a low mileage car, Arizona heat has not been real easy on some parts of it. I'm fixing all that. My '85S has always been garaged and has lived in the temerate climate of the Northwest and seems to have faired a bit better. The person who drove the 88S drove it to work and parked it outside. While the NW has moisture, and Arizona doesn't, there are no signs of salt damage ever and most looks to be near new in shape. Part by part, I'll get it.
Harvey