'80 Headlight question (I know, another headlight ??)
Thread Starter
Instructor
Joined: Jan 2012
Posts: 176
Likes: 25
From: Plainfield Illinois
'80 Headlight question (I know, another headlight ??)
I have searched but can't find a definitive answer.
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
I have searched but can't find a definitive answer.
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
https://www.corvetteforum.com/forums...post1582899071
Last edited by Kacyc3; Aug 29, 2017 at 05:29 PM.
Thread Starter
Instructor
Joined: Jan 2012
Posts: 176
Likes: 25
From: Plainfield Illinois
Unless I replace every component, I highly doubt that it will be cheaper to go with an electric conversion over fixing the current system. Don't get me wrong, I would love to go electric but I cannot see spending that kind of money on something when it should be a fairly cheap fix to repair it. I'd rather put the money into some other mod.
go electric, smoother more reliable and usually cheaper than fixing the vacuum setup.
https://www.corvetteforum.com/forums...post1582899071
https://www.corvetteforum.com/forums...post1582899071
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)
Thread Starter
Instructor
Joined: Jan 2012
Posts: 176
Likes: 25
From: Plainfield Illinois
Already studied it
Going to start testing the actuators, relays and switch when I get the hand pump and gauge
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
Unless I replace every component, I highly doubt that it will be cheaper to go with an electric conversion over fixing the current system. Don't get me wrong, I would love to go electric but I cannot see spending that kind of money on something when it should be a fairly cheap fix to repair it. I'd rather put the money into some other mod.
Burning Brakes
Joined: Jan 2012
Posts: 943
Likes: 73
I have searched but can't find a definitive answer.
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
The lights do not go up or down with the headlight switch.
They were operating just fine and then one night, nothing.
I checked the route of all hoses and they are correct
I don't have a vac gauge or tool to apply vacuum yet so figured I'd post here to see if anyone had insite before I track down tools and start testing individual parts.
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
I removed the connection at the check valve and connected it directly to the line going to the front of the car, but nothing happened(with car running). I then put the shop vac on that same line and the right went up slowly but the left went up about 2" and then stopped(like it was weak vacuum) Shop vac creates way more than the carb.
The under dash switch did nothing.
I suspect that one or both actuators are leaking and/ or the vac can is
http://repairs.willcoxcorvette.com/c...uum-schematic/
It could also be a cracked hose end where it connects to a fitting. My system turned up multiple problems (relay, actuator, cracked hose) not just one.
Last edited by BlackC3vette; Sep 1, 2017 at 06:40 PM.
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Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
I did use a shop vac at both actuators and they both went up quickly but the only way to get them down was also with the shop vac on the other line.
The headlamps have two separate vacuum systems--one for operation and one for control.
The control system includes the headlamp switch, override switch and the small vacuum lines that connect at the top of the relays. Once you get the hand vacuum pump I suggest first testing the control part of the system. Disconnect the small line near the brake booster and apply vacuum. It should only take a few pumps to get significant vacuum and it should hold indefinitely. If you can't draw a vacuum I suggest first disconnecting the small lines at the relays (one at a time) and then plugging the line to see if you can draw vacuum. If you still can't draw a vacuum disconnect the control line for the relays at the "tee" and plug there.