72 headlight doors

[Fred H.]

We encountered that the headlight doors open when activated but very slowly (and one lags the other). Closing the doors has the same problem (one lags the other), We've replaced the original headlight actuator relay valve with reproduction valve (from Pacifica Corvette). I've seen conversations that many of these re-pop components are junk. Any advise is welcomed

[Patrick H.]

Re: 72 healight doors

I think you answered your own question.
I would have all 4 of the original valves redone by Bob Demmel (headlight x2, wiper in right fender, wiper inside trough).
Also, if your silver check valve by your intake is a reproduction, some of those are also faulty.

[Fred H.]

Re: 72 healight doors

Thanks Patrick, we did have both headlight canister's and the headlight canister (at the firewall) redone earlier. However we didn't have the OEM headlight door vacuum redone and the silver check valve we believe is original (it might be part of our problem)

[Patrick H.]

Re: 72 healight doors

Fred,

Not the canisters, the black ported relay valves.
There are 3 that are the same, one that is different.

[Brian M.]

Re: 72 healight doors

Visit WillcoxCorvette.com for repair videos or you may even call them. Good luck.

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You used the vacuum pump to pull the door open did you check for vacuum on the wiper actuator relay. The relay controls what the actuator does and should have vacuum on the small hose to close and no vacuum on the small hose to open. So go to the relay and see if it's working first.... then I'd start working backwards from there going to the wiper arm vacuum switch and then to the over-ride and then to the solenoid.

The tach solenoid when energized cuts vacuum off from the system and makes the small hose side lose vacuum (same as the over-ride switch under the dash). So when you turn on the wipers the solenoid blocks the vacuum on the blue hose at the over-ride switch. So to check operation, pull the hose off the over-ride with the wipers off you should have vacuum on the blue hose and it should drop off when you turn on the wipers.

The video below on the wiper arm vacuum switch is the only one out there that properly test this switch. There is another one out there but it doesn't test from the correct nipple, this switch must be tested from the center port not the lower port.

Willcox





69-72 Wiper Arm Vacuum Relay testing.



1969-1972 Corvette Wiper Arm Vacuum Switch Test

[Rex M.]

Re: 72 healight doors

I'm no expert on the vacuum system or how the doors open but... I have a 70 Vette that's pretty much all original. I lay down in front of the car and look up at the headlight doors. I spray WD40 using the plastic tube that comes with the spray can, on all the moving hinges. After I'm done the doors work just fine for a couple years. Then it does it again; one side smacks down and other side is slow opening. Get down in front and did it again and it works fine again. Its worth a try. It don't take much for the doors to screw up. Good luck.