Headlight Vacum
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Joined: May 2008
Posts: 81
Likes: 0
From: Annandale Virginia
Headlight Vacum
The headlights on my 76 don't come up on their own. When I turn on the switch, the driver side tries to come up then sinks back down.
I've checked the vacum hoses and there is vacum to the resevoir tank and other connections. The relays have vacum in the red (closed connection at the top) The driver side at the bottom (green line) had no vacum. I went on to check the passenger side relay and found that it has vacum and when I plugged the green line with the gauge to get a reading the driver side head light went up.
I can get the driver side to go up using the vacum pump. I can't get the passenger side to come up with the pump.
I think my problem is that the passenger side acuator has a leak. Does that sound right? Do you guys think I should try and replace the seals on it? How do your trouble shoot the actuator?
Thanks for your help.
I've checked the vacum hoses and there is vacum to the resevoir tank and other connections. The relays have vacum in the red (closed connection at the top) The driver side at the bottom (green line) had no vacum. I went on to check the passenger side relay and found that it has vacum and when I plugged the green line with the gauge to get a reading the driver side head light went up.
I can get the driver side to go up using the vacum pump. I can't get the passenger side to come up with the pump.
I think my problem is that the passenger side acuator has a leak. Does that sound right? Do you guys think I should try and replace the seals on it? How do your trouble shoot the actuator?
Thanks for your help.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Sounds like the seal is bad in the passenger side.Yes I would try the seal.You can only fix the green side of the actuator.You should put a vacuum on the red side and make sure the diaphragm is OK and if it holds vacuum renew the seal.
Le Mans Master
Joined: Aug 2006
Posts: 7,426
Likes: 1,559
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Safety Car
Joined: Oct 2007
Posts: 4,380
Likes: 1,742
From: Seattle Area Washington
I think this is a good link for head light repair especially resealing the actuators. I haven’t needed it yet
but looks very detailed.
http://www.corvettemagazine.com/content/view/86/
but looks very detailed.http://www.corvettemagazine.com/content/view/86/
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Intermediate
Joined: Nov 2007
Posts: 48
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From: LAKE PLEASANT NEW YORK
I HAD THE SAME PROBLEM W/MY 75. GOT TWO NEW ACUATORS
AND RELAYS FROM ZIP. MOST OF THE TIME ITS JUST THE RUBBER SEAL
GONE BAD BUT YOU HAVE TO TAKE IT OUT ANYWAY. ZIP HAS GOOD TECH ARTICLES (WITH PICTURES) IT WAS NOT THAT BAD BUT COVER HOOD AND FRONT BUMPER ITS TRICKY GETTING THEM OUT.
NOW THEY GO UP REAL FAST AND DOWN. GOOD LUCK JOHNNY75
AND RELAYS FROM ZIP. MOST OF THE TIME ITS JUST THE RUBBER SEAL
GONE BAD BUT YOU HAVE TO TAKE IT OUT ANYWAY. ZIP HAS GOOD TECH ARTICLES (WITH PICTURES) IT WAS NOT THAT BAD BUT COVER HOOD AND FRONT BUMPER ITS TRICKY GETTING THEM OUT.
NOW THEY GO UP REAL FAST AND DOWN. GOOD LUCK JOHNNY75
Le Mans Master
Joined: Aug 2006
Posts: 7,426
Likes: 1,559
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Zip has bad connections!
If you look at the hose routing in picture # 15 they have the connections WRONG! On the headlight switch the hose connection closest to the firewall should go to the bottom connection on the pull down switch. PG.