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Headlights stop at 45 degrees

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Old 02-13-2018, 03:11 PM
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onionpatchkid
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Default Headlights stop at 45 degrees

My 1979 Porsche 928 had 2 different colored headlight lamps so I bought 2 new bulbs. I pulled out the screws holding the shrouds on and pulled them back to reveal the bulbs but did not remove them all the way. I changed the bulbs. The shroud screws had rusty heads so I decided to paint the screws. While waiting for the paint to dry I decided to fix the moulding on the passenger window. I turned on the key to roll down the window and the headlights retracted pushing the shrouds down into the fender/wheel well and met resistance and scratched them up. I got them out and re-installed but now when I turn on the headlights, they go up and stop at 45 degrees and point to the sky. When I turn them off they do move physically all the way forward and then all the way back and retract down to flush with the hood like normal. I think the limit switches have been moved but I can't find them. I have the cube relay pulled and the lights manually raised to the upright position so I can drive the car. The headlights work.
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Old 02-13-2018, 03:50 PM
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For purposes of clarification- did you remove the screws to paint them leaving that shrouds sat over the headlamp assembly but not secured as it were?

If so it kind of sounds as though the shrouds immediately displaced when the assembly retracted, possibly causing the retraction to jam, the motor had no clue as to what was happening and as a consequence possibly the motor shaft slipped relative to the spines and is now out of phase as it were. Whether or not the splines are damaged remains to be seen- perhaps you can remove the conrod and inspect the motor shaft and conrod splines for signs of damage.

It will be interesting to see what other suggestions the brains trust come up with on this one.
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Old 02-13-2018, 04:16 PM
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Default 928 Headlight motor limit switch problem?

Originally Posted by FredR View Post
For purposes of clarification- did you remove the screws to paint them leaving that shrouds sat over the headlamp assembly but not secured as it were?

If so it kind of sounds as though the shrouds immediately displaced when the assembly retracted, possibly causing the retraction to jam, the motor had no clue as to what was happening and as a consequence possibly the motor shaft slipped relative to the spines and is now out of phase as it were. Whether or not the splines are damaged remains to be seen- perhaps you can remove the conrod and inspect the motor shaft and conrod splines for signs of damage.

It will be interesting to see what other suggestions the brains trust come up with on this one.
That's exactly what I did. I just pulled them back out of the way about 3-4 inches but left them sitting there not attached. When they retracted, the lights took them down into the wheel well and you could hear/feel that they were hitting each other. I sat in absolute horror as it was happening in what appeared like slow motion. I totally knew better too but I was caught up in the moment that the rusty screws had come out ok without snapping off the heads. That's what I thought would happen with this project. I just forgot that when the lights are left up and you turn the key on, they retract automatically. So stupid of me.
How do I get it back into the correct phase? Do I have to pull the motor? I hope not, it's tight down there. Could it possibly be the headlight relay? Is it timed?
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Old 02-13-2018, 04:30 PM
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You only qualify as a ******** when you manage to put the conrod through the a/c condenser as plenty have done previously!

There are some differences between the way your model year works and that of mine but as I understand the principals are similar. The lift motor is driven from the relay but the motion is controlled by wiper contacts on the end of the motor that wipe over metal and ceramic surfaces- one conducts the other [obviously] does not. To set mine I disconnect the conrod from the motor, turn the headlights on until the motor stops [get a friend to turn on the headlight while you watch the motor shaft turn and then stop]. At this point I manually lift the headlights up fully [they are free to move with the conrod disconnected], then get your friend to hold them in the upright position while you refit the conrod to the motor output shaft.

I trust this will work for your model year but doubtless others will chime in if that is not the case. Main thing at the moment is to make sure there is no irreversible damage to the motor shaft or conrod assuming my theory is in fact correct.
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Old 02-13-2018, 04:41 PM
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You're the man. I've been struggling with this for over a month. I can't find a mechanic that works on 928's around Portland OR. I'm hesitant to pay someone to learn on mine. I'm an electrician (not auto) so I have decent troubleshooting skills but this really helps me. Thank you and I'll let you know what happens.

Doug
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Old 02-13-2018, 04:46 PM
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Old 02-13-2018, 04:58 PM
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Before you re-connect the conrod just switch the lights on and off a couple of times to make sure the motor is spinning correctly. My motor spins in one direction to lift and the other direction to retract. I have a feeling yours may work a bit differently as in it spins the same direction for both up and down movements.Just check this out before reconnecting the conrod- that or wait until your fellow countrymen are back home at their computers and can give you a more definitive guideline.
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Old 02-13-2018, 05:04 PM
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But definitely I want to disconnect the rod down low at the motor spindle so that the lever doesn't go through the radiator right? I've heard about that.
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Old 02-14-2018, 12:47 AM
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You were right on the money. Where the rod is connected to the motor shaft, it's just a slip fitting held tight with a 10mm nut. The force of pinning the shroud had repositioned the slip fitting out of phase. It was a bugger but I fixed it by myself. I owe you a case of beer. Look me up if you come to Oregon. What a relief! Thank you!
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Old 02-14-2018, 01:08 AM
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Originally Posted by onionpatchkid View Post
You were right on the money. Where the rod is connected to the motor shaft, it's just a slip fitting held tight with a 10mm nut. The force of pinning the shroud had repositioned the slip fitting out of phase. It was a bugger but I fixed it by myself. I owe you a case of beer. Look me up if you come to Oregon. What a relief! Thank you!
Pleased that you got a quick and hopefully not too painful result. That is the entire point of the list. If you want to help do yourself a favour and take out a paid subscription to the list- does not cost much and you only need a result once for it to pay for itself value wise.
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