Headlight operation

[fatboy]

I am sure this has been ask alot,but I will ask.If the car is running the headlight doors will go up and down normally.If the car is off,half of the time the drivers side will go down after a delay.I have checked hose connections.What next?

 

[TJay]

Here's a diagram for the headlight vaccum system. Check the actuator or hoses for leaks, also check the relay for the problem side.

 

[jdp6000]

I think its because you have leak in the driverside headlight. Sounds like you have enough vaccum when the engine is going but when off because of a mild leak it slows down the operation.

I can't remember if its the front seal or rear seal that operates the function. Any way its usually the seal in the front of the actuator that goes. Open the lights. Take off the trim piece around the head light. Look for the actuator rod. Should have a rubber coil shaped boot over it. Pull the boot up to access the seal boot (shaped like a magicians hat). Check for tears.

Link to what it looks like and where you can get it http://www.ecklers.com/product.asp?pf_id=A8263&dept_id=1476

 

[srs244]

it is easier to access the dust boot and the seal by removing the front grill. it is the recommended method of servicing the actuator. as mentioned, with the engine OFF, raise the headlamp doors by pushing upward on the door adjustment bolt to raise the door a bit, then by grabbing the door from the top side and lifting until it locks into place. at that point, the boot and behind it the seal can be examined. the dust boot is really secondary to the whole deal and is designed to protect the seal. if it is damaged, it shouldn't affect the operation of the actuator. it is the seal (magician hat shaped as noted above) that usually is the problem. in rare cases the actuator diaphram goes bad at which point the entire unit needs to be replaced. unfortunately the vacuum headlamp (and wiper in some cases) systems on the C3's is frustrating to work on and hard to pin-point the exact problem without going through a process of elimination excercise.

 

[red70vette]

You should shut your headlights when the car is running.

When new the car probably had a tight enough system to be able to turn the car off and then retain enough vaccum to close the headlight doors. That was 30 years ago. If you spend about $300 and about 50 hours of labor you can probably get the system back to original specs and be able to close the doors when it is shut off.

For me I turn off the lights then shut the ignition. Much easier. I have enough other issues that need to be dealt with than to try to correct that one.

 

[fatboy]

Thank you everyone for the advise.This is all very helpful.Good diagram Makes it easy to understand system.