bronco68

I am experiencing an issue with my headlights. all of a sudden they wouldn't come up when the switch was turned on. i can open them manually and they will stay on while running. if i pull the vacumn switch under the dash, they will stay up after engine is turned off. i pulled 25 inches of vacumn to the system and it will hold vacumn with engine off. where should i start. no vacumn leaks and everything works fine except coming up. the engine has 18 inches of vacumn at idle.
thanks
frustrated vette owner

justaguy10825

Bad light switch???

bronco68

Does the light switch have a trigger to control the headlights? Is there a relay that controls the up down?

Easy Mike

Yes. There is a vacuum line to the headlight switch. Pull the switch to turn on the lights and you send a vacuum signal to open the headlight doors.

The override under the dash bypasses the headlight switch and allows you to cycle the headlight doors a time or two with the engine off.




(I apologize for the original diagram. There are two of these available, an incorrect version and a correct one. I thought I had deleted the bad one, but --naturally-- deleted the good one.)

bronco68

Thank you very much.

...Roger...

Bronco the above vacuum diagram is wrong don't use it your headlights won't work correctly.

bronco68

Thank you for the heads up. i will trace thelines before i do any replacements.

Peterbuilt

Here's a corrected diagram. PG.

bronco68

Thank you,
i see where the location of the lines are different at the headlight switch.

Peterbuilt

The troubleshooting guide at www.corvette-101.com/ is helpfull. PG.

21boy

You're lights turn on though when you pull your switch, just not up? Sounds like either the switch isn't holding well or perhaps the relays may have an issue???