NC928S4

Recently my headlights have decided to not fully retract when I turn them off. They do retract about 95% when light switch is turned off. Once in this position the lights will no longer rotate up or turn on when lights are turned on again. I must manually turn the headlight **** to retract the lights into the fully parked position. Then they work correctly for 2-3 on-off cycles but eventually go back to not fully retracting.

I have not been doing any work under the hood recently and the last related thing I can think of was the Deoxit job of the fuse and relay panel.

Any ideas on what is happening?

Thx

martinss

It looks like what happens when the motor over rotates. On S4s and later, the headlight lift motor goes in one direction to raise the lights and in the other direction to lower them. The top and bottom positions are sensed based on a set of fingers making contacts on a gear in the gearbox:



If the top position is not correctly sensed, the motor continues and the arm over-rotates, starting down the backside until it strikes the condenser. Alan developed a shield to protect the condenser for those of us who have experienced this problem.

When you manually turn the motor, do you have to first raise the light for it to then continue down? If not, then it may be another issue.

dr bob

Also--

The light isn't rgidly connected to the crossbar. In fact, you can go lift a headlight manually from the parked position and pull it straight up to deployed position. Let it go and it falls back.

--- Put the headlights in the full-up position, then turn the key off. Gently push back on the obe that worn't fold back a,d you might feel it reengage.

--- Look carefully at the area under the offending headlight to see if there;s something limiting the downward movement. Something is doing it.

--- There's a stop bolt that supports each headlight in the parked position. See it it got moved, or has something sitting on it.

MainePorsche

Also, are the 3 bolts that affix the motor/plate in place tightened to a fixed status ? Any play there will throw off the linkage movement I think.

dr bob

... between the little crank on the motor and the arm on the headlight crossbar. The ends are assembled with white plastic (nylon?) bushings, a washer and a circlip on each end. Once in a while, one of the clips comes off, the linkage bar gets a little crooked, an arm gets bent, the link falls off, and the motor drives the link through the AC condenser and the radiator.

This probably should sit at the top of the "things to check first!" list for problems with headlight motion.

NC928S4

Thanks for the multiple things to check. Sadly, the condenser is damaged which also explains why my A/C which I finally had working is now blowing hot air.

It looks like Martin, Craig and Dr Bob are all correct and I need to dig into find the root cause.

When hand raising to full position all rotates without issue. When hand lowering there is no stop position and I can continue rotating until the lever bars rotate into the condenser. So my initial description on not fully retracting was incorrect. The mechanism was over rotating/retracting thus raising the lights to the position in the picture. The stop point was the condenser coil. Damn!

I checked the nylon clips briefly and all looked okay but will check more thoroughly in daylight tomorrow.

NC928S4

I inspected the headlight raising mechanism and both nylon bushings and cir-clips are in place and look healthy. No levers were bent either.

After manually adjusting the lights by hand I proceeded to try and reproduce the failure but the light retracted perfectly 10-15 times as expected. But on one cycle, the mechanism shuttered so I decided to check the tightness of the 3 bolts Craig pointed out. They weren't finger loose but each of them required a 1/4 to 1/2 turn. I then cycled the light another 15+ times with no issues.

Not sure how or why they decided to loosen themselves but they were loose and I have not been in there before.

Since summer is just about over I'm going to hold off installing a new condenser in the case that something else may be going on but the bolts were definitely loose.

This is a nice touch of German engineering - If a slight alignment problem on headlights occurs then take out A/C condenser and make the bastard sweat.

MainePorsche

Not really a winner...just wanted to offer a suggestion for a potential cause that had not been suggested yet with the other good ones. I added a touch of Blue Loctite to my bolts there as there is a lot of torquing from the torsion bar through to the linkage arms, and a good 'bite' is better.

928Collector

Gentlemen:

I think i have everything down except how to remove the actual head light motor - any advice?
I've removed the front grill.
have removed the three screws
have removed the center screw
have disconnected the wires
Some prior posts suggest using a screw driver and prying the arm away from the motor but when i tried this there wasn't sufficient space to force the motor laterally enough for the arm to clear the length of the center screw. Am i not pushing it hard enough? Should i force it at the risk of bending the arm?
Should the arms be manually raised to position the motor up away from the side panel?
Any advice much appreciated.

three blue arrows screws and one red center screw removed

How do i remove these circlips? a simple screw driver doesn't pry the motor away nor does it wedge/lightly hammer out these circlips