1979 Headlight Troubleshoot
Thread Starter
Heel & Toe
Joined: Apr 2014
Posts: 16
Likes: 0
1979 Headlight Troubleshoot
I noticed my passenger dim bulb went out so I bought the bulb and went to replace it today and my headlights wouldn't come up at all.. They've never not come up but my passenger has always been a little lazy haha. I pulled the release valve and it releases air but nothing happens. I took off the main line going into the Y connection and my headlights popped up. So I changed my headlight but I'm still having trouble finding the culprit of my headlights not coming up on their own. Also does the vacuum always have compression even when the headlight switch isn't pulled?
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
After the day I had today.....I would go on Willcox's web site and look for a headlight vacuum troubleshooting guide.
Vacuum and compression are two different thing entirely.
You either have a bad headlight switch, vacuum hoses not routed correctly, vacuum check valve bad, actuator relays leaking and the vacuum actuators (pods)are leaking and need new seals or replacing.
The system is easy to diagnose.
DUB
Vacuum and compression are two different thing entirely.
You either have a bad headlight switch, vacuum hoses not routed correctly, vacuum check valve bad, actuator relays leaking and the vacuum actuators (pods)are leaking and need new seals or replacing.
The system is easy to diagnose.
DUB
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
First I'd check around the relays and the actuators and make sure you didn't knock a hose off.
If you removed the black/white hose at "L" and the lamps came up... Go to the headlamp switch over-ride and pull it down.. see if the lamps open. If it does, then pull the hose "H" off the over-ride. You should have vacuum there with the lamps off. Pull the lamp switch on and see if it blocks the vacuum on that hose. If it does, the switch is good, if it fails replace the switch.
If you removed the black/white hose at "L" and the lamps came up... Go to the headlamp switch over-ride and pull it down.. see if the lamps open. If it does, then pull the hose "H" off the over-ride. You should have vacuum there with the lamps off. Pull the lamp switch on and see if it blocks the vacuum on that hose. If it does, the switch is good, if it fails replace the switch.
Thread Starter
Heel & Toe
Joined: Apr 2014
Posts: 16
Likes: 0
First I'd check around the relays and the actuators and make sure you didn't knock a hose off.
If you removed the black/white hose at "L" and the lamps came up... Go to the headlamp switch over-ride and pull it down.. see if the lamps open. If it does, then pull the hose "H" off the over-ride. You should have vacuum there with the lamps off. Pull the lamp switch on and see if it blocks the vacuum on that hose. If it does, the switch is good, if it fails replace the switch.
If you removed the black/white hose at "L" and the lamps came up... Go to the headlamp switch over-ride and pull it down.. see if the lamps open. If it does, then pull the hose "H" off the over-ride. You should have vacuum there with the lamps off. Pull the lamp switch on and see if it blocks the vacuum on that hose. If it does, the switch is good, if it fails replace the switch.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
With the switch off, pull the hose off the over-ride see if the blue and black striped hose has vacuum. It probably will.
Next I'd go to the hose connection L and pull that hose off and check for vacuum on it. You should have vacuum there too. (with the switch off).
If you do, I'd look at the relays and see if all the hoses are connected properly. check the large yellow hose for supply vacuum. If you have vacuum on M and N then the lamps should stay closed. Pulling hose off at L or pulling the hose off the top of the relay should result in the headlamps opening.
If you want to test the relay there is a video for how to do this.. and a good pic on the site. Same with the actuators.
Willcox
Next I'd go to the hose connection L and pull that hose off and check for vacuum on it. You should have vacuum there too. (with the switch off).
If you do, I'd look at the relays and see if all the hoses are connected properly. check the large yellow hose for supply vacuum. If you have vacuum on M and N then the lamps should stay closed. Pulling hose off at L or pulling the hose off the top of the relay should result in the headlamps opening.
If you want to test the relay there is a video for how to do this.. and a good pic on the site. Same with the actuators.
Willcox
1st Gear
Joined: Aug 2014
Posts: 1
Likes: 0
Headlight issues
Hey everyone, i am new to the forum and want to take the time to thank everyone in advance for the help.
my issue that i am having is the drivers side headlight come up but doesn't go down when i turn the headlights off.
after i have turned the car off, if i gently push on the top of the headlight, it will slowly retract. i have read through other similar issues, however most are the headlights are not coming up. i am thinking that the Actuator may be bad. am i right for suspecting this as the issue?
-Andy
'79 stingray
my issue that i am having is the drivers side headlight come up but doesn't go down when i turn the headlights off.
after i have turned the car off, if i gently push on the top of the headlight, it will slowly retract. i have read through other similar issues, however most are the headlights are not coming up. i am thinking that the Actuator may be bad. am i right for suspecting this as the issue?
-Andy
'79 stingray
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