Classic75

Ok, I have searched through the forum, but nothing I have read seems to apply to what I have going on. My Vette is a 1975 .

First my headlights wouldn't do anything, go up or down.... so I started going through the whole system (engine side of car) with a hand held vacuum pump.

First, I went ahead and replaced the vacuum hose filter and vaccum hose check valve.

Next when testing the vacuum on the actuators I found one was not holding vac on rod seal side (drivers side), so took it out and replaced rod seal (witches hat).

Next I found that neither of the relays would hold vacuum, replaced both with new ones.

Now the headlights open and close, but when I turn them on there is like an 18 second delay before anything happens (seems much much longer, but I timed it) and then the passender light comes open first and then about 3 to 5 seconds later the drivers side comes up.
Also, they both open pretty slowly.

They close perfect, nice and fast. Boom.

Also, when I turn the car off and then try to close headlights, nothing happens. I tested the vacuum on tank and it seemed to hold fine.

Any help would be appreciated!!

CCrane65

When you tested the actuators did you test both sides? Slow to rise headlights sounds like leaky actuator on the back side. Check the circuit with the green hoses as those are the ones used to open the headlight doors.

cc

...Roger...

Do they still have the delay if you use the pulldown bypass to open the headlights ?

Aggitated Monkey

You most likley need to replace your actuators. Before replacing you can spray some wd40 into the lines (extend/retract) and operate them. This some times is the fix if they are not too far gone. You should do well with the wd40 are they are opening and closeing slowly.

Classic75

Yes I tested both sides of the actuator. The back sides on both held vacuum.

Interesting - I just noticed that if you pull the bypass the delay is about half as long.... still a noticeable delay, but about half as much. Also, they opened in the opposite order as when I pull the light switch. This time the drivers side comes up, then the passenger.

Spray WD40 directly in the back side input of the actuator?

Roadster71

While you have the WD-40 out give all the hinge point a good bath. They get cruded up over the years and could cause your problem by thmselves.

dgood

classic 75, I had the same problem with my 79. I replaced the seal that is under the rubber boot on the acutator. it is part number A8263 in the ecklers corvette book. it is called the actuator seal. Real easy to replace, pull the actuator out, remove the rubber boot, remove the seal retaining ring and slide the seal on. I am assuming your headlights are made like the 79s. alot cheaper that $90 per actuator.

Mike Ward

Yikes.

dgood

misprint. the seal is 9.99 and the actuator is 99.99

CCrane65

Remember, you are sucking that stuff into the engine via the vacuum reservoir, check valve and filter.

cc

Classic75

So what you are saying is don't spray Wd-40 in there?

Mike Ward

Yes, there's nothing inside an actuator that will benefit from WD40. It's a metal can with a rubber diaphragm.

Classic75

That's what I was thinking... I did replace the seal on one already.... but I am willing to try anything at this point. I am going to replace the seal on the other one for the heck of it. Especially as I see now how I can do it in place instead of taking the actuator out... any other thoughts on what else this could be would be appreciated.

Classic75

One tip for anyone who wants to take the actuator out. After spending at least a half an hour turning it in a million directions trying to get it out throught the front grill opening as is directed in the corvette magazine article I found on-line (and removing the horn to make room etc...)... I found it MUCH easier to pull the hood forward with one hand (it moves another 1/2 inch or so towards front of car when open) and then I slipped it back in the gap from behind the mounting bracket. Took like two seconds. Of course you have to be very careful not to scratch the hood of your car.

76 VETTE

I am going to try that one.I am in the process of replacing one.

Aussie79

Actually, I found getting the units out wasnt hard, yes you need to be careful of the hood but more importantly, be extra careful not to crush your A/C evaporator core.

Dennis.

Classic75

Honestly I am going to try and do the other one in place, without removing it. Now that I have done the one, I think it won't be to hard from underneath the car.

Aggitated Monkey

The first time I read this I too thought what the ?? and on my last car when I thought for sure I needed new actuators I sprayed the WD40 and they worked. On my 78 now my lights were a little slow and I sprayed the WD40 and again they work perfect.

In worst case the OP may have to replace the actuators.

76 VETTE

That does work by pulling the hood forward.I just wrapped the actuator in a cloth and that way it didn't scratch anything.2 seconds and it's in.