If you look at diagram http://www.spectracreations.com/corv...ges/vacsys.jpg it appears that vacuum from the intake goes through the hoses through the headlight switch and bypass (when closed) then through the hoses to the tee then to the top of the relays. Once the headlight switch is opened a vacuum leak is created and acts on the relay allowing the relay bellows to be forced down by vacuum causing vacuum to be routed the the back side of the actuators thus lifting the headlights. I ran the test on the switch such as

"HEAD LAMP SWITCH TROUBLESHOOTING: When closed (**** pushed in) attach the vacuum pump to port 2 (back port) and block port 3 (front port). Vacuum pressure should be maintained. When open (**** pulled out), port 3 will not hold vacuum."

I attached the vacuum pump to port 2. Vacuum pressure did hold. The vacuum held with the switch closed as it should but also when the headlight switch was pulled
:confused: :confused:
Local Vette gurus say if the switch was bad it would not hold vacuum in either the open or closed position. Mine holds vacuum either way. Based on my analysis I say the switch is bad because it will not cause a vacuum leak as it should in the open position. I have to pull the headlight switch then the bypass to open the lights, and of course with new actuators and relays they open crisp and fast and at the same time :cheers: HELP ME TO FIGURE OUT IF THE HEADLIGHT SWITCH IS BAD OR NOT. Do not wish to spend $$$/ rip apart the entire dash to put in a switch that maybe/ maybe not bad. PLEASE PLEASE HELP!

David


[Modified by Cali,77,L-82, 6:37 PM 9/14/2002]


[Modified by Cali,77,L-82, 6:38 PM 9/14/2002]


[Modified by Cali,77,L-82, 6:38 PM 9/14/2002]

 

FAUXRS you were right the headlight switch does NOT cause a vac. leak. Vacuum is held blocked against the closed headlight switch. Once the switch is pulled or the bypass is pulled vacuum travels from the intake to the top of the relays pulling the bellows up opening a port to send vacuum to the front of actuators pulling the bellows/ linkage and light assemblies up. So I think the problem is the headlight switch is blocked off at all times not allowing vacuum to register onthe top of the relays. Your idea about testing the bypass proved this to me. Thanks David.

 

There are two vacuum systems to test.

The control system is everything you mention in the first paragraph. An easy way to test this is with a vacuum guage at the actuator relay.

The other system moves the headlights. These are the two big lines coming into the actuator relay (which just acts like a switch) to direct vacuun to one side of the actuator or the other.

Test the systems independently.

There's a great guide for troubleshooting vacuum available from Ecklers or any of the c3 vendors.

Your references to ports are a bit confusing (which is easily accomplished). Since both systems are never really open, I would expect them to "hold" vacuum (unless you create an opening).

As they say, Vacuum Sucks.

 

I GOT IT! Check this out. In normal state the engine provides vacuum routed through the switch/ bypass and to the top of the relays which compensates and overcomes the spring tension in the relay. Upon opening the switch or bypass the vacuum port is blocked and upon decrease in vacuum the spring in the relay closes and moves down opening the green port which allows vacuum to the front of the actuator thus opening the headlight doors. I tore apart the old relays/ bypass that I had in the trash can and saw how it operated/ worked. So the headlight switch for whatever reason is not blocking the vac. port. however the bypass does work. I ran a vacuum guage splitted off the relays while my girlfriend operated the switch/ bypass and watched how vacuum was affected.

GOD I'M SMART!! :lol: :lol:

 

Well ordered the headlight switch/ bezel/ nut today from MA. Nothing else to replace. :rolleyes: