Headlights Now Won't Go Up
Thread Starter
Heel & Toe
Joined: Mar 2003
Posts: 16
Likes: 0
From: saint james New York
Headlights Now Won't Go Up
I need some HELP on getting my headlights to go up.I have a 73 vette that I have been restorting for the last few years.I have had no problems with them going up & down during this time.Then all of a sudden one day they went up when I tried it again they didn't & haven't since.Sure now that I have completed the whole car and ready to use it the lights won't go up.I have never replaced ANY components regarding the system as it worked leave it alone.I have done a breif check (no gauge)and seem to have good vacuum off the intake and have checked backwards from the filter,check valve,to the door actuator (but not the actuator relay valve) and have vacuum.Before I start the car I can raise them manually and they will stay up while the car is running but go down when I shut the car off.I then can't manually raise them for a little while.I don't know how to diagnose or where or how to start.If any one has suggestions,tips,a past experience or what to do please send me a note or call 631-361-0041.Thanks Bill
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
Here's a schematic of the vacuum system if it helps. Will the doors open with the manual over ride switch under the dash? Check to make sure all the hoses are on correctly under the dash.
Racer
Joined: Jun 2002
Posts: 281
Likes: 0
From: Brookfield IL
1. Make sure you don't have the hoses crossed at the actuator itself.
2. Do you have vacuum at the small hose (typically white striped) at the top of the actuator relay? You need vacuum here to hold the headlights closed. Without this control vacuum, the headlights will by default open.
2. Do you have vacuum at the small hose (typically white striped) at the top of the actuator relay? You need vacuum here to hold the headlights closed. Without this control vacuum, the headlights will by default open.
Pro
Joined: Mar 2003
Posts: 553
Likes: 1
From: Valparaiso IN
Thread Starter
Heel & Toe
Joined: Mar 2003
Posts: 16
Likes: 0
From: saint james New York
Thanks For your help.Yes by moving the manual override switch in & out it does allow me to open & close the headlights.But still won't work at the headlight switch. What does this tell me as to what is wrong or needs to be replaced.next step?.Thanks again Bill
Racer
Joined: May 2006
Posts: 264
Likes: 0
From: Fort Myers, Fl / St. Paul, Mn
Does pulling the headlight switch feel different now. The second time I pulled my headlight switch the vacuum portion of the switch let go. Now it pulls out very easy - and I now have to use the override under the dash to open them.
Thread Starter
Heel & Toe
Joined: Mar 2003
Posts: 16
Likes: 0
From: saint james New York
No, there doesn't seem to be any difference at the headlight switch when I pull it to turn on. The head lights go on but do not raise. For now pushing the manual override switch in or out makes them go up or down.I'm thinking maybe it's the head lamp relay vave?.Any thoughts.Thanks Bill
Racer
Joined: Jun 2002
Posts: 281
Likes: 0
From: Brookfield IL
The headlight switch and override switch and connected in series. In normal configuration (headlights off), both switch are open (the two hose ports are connected to each other). This then provides a path for the vacuum to reach the actuator relay's top port. This vacuum is necessary to hold the headlights closed. When you pull the override switch, it is disconnecting the two ports. This then blocks the vacuum and the headlights open.
Once you understand this, you now know that your headlight switch must not be disconnecting the two ports when you pull the switch. In other words, vacuum is still getting to the actuator relay, which keeps the headlights open.
I would say that the switch is bad, or, less likely, that the vacuum hoses are currently bypassing the switch. You should be able to look under the dash and see a hose going from the headlight switch to the override to verify it is in the vacum path.
I would disconnect this hose at the override end and put a vacuum gauge on it. Then I would start the car and see your nominal engine vacuum on the gauge. Then pull the headlight switch and verify the vacuum is not going away (it should on a good switch).
At least you can operate ethe headlights until you replace the switch.
Once you understand this, you now know that your headlight switch must not be disconnecting the two ports when you pull the switch. In other words, vacuum is still getting to the actuator relay, which keeps the headlights open.
I would say that the switch is bad, or, less likely, that the vacuum hoses are currently bypassing the switch. You should be able to look under the dash and see a hose going from the headlight switch to the override to verify it is in the vacum path.
I would disconnect this hose at the override end and put a vacuum gauge on it. Then I would start the car and see your nominal engine vacuum on the gauge. Then pull the headlight switch and verify the vacuum is not going away (it should on a good switch).
At least you can operate ethe headlights until you replace the switch.
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