[flyboy]

Anyone out there that could advise on how to diagnose hidden headlights on my 69 GTO? Shut the car down with lights on. I pulled the doors up by hand, which I had done a time or two before (I know, stupid and lazy). Now both doors work fine opening, but neither make any attempt at closing. If I close by hand, they start drooping. I have good vacuum out of carb, traced all lines from the headlight switch to the actuators, all of which are relatively new. I doubt both actuators would go at same time, and with both only opening and not closing. I am leaning toward headlight switch, but no idea how to diagnose. Does anyone out there have any suggestions? I hate to start swapping parts to figure it out. Thanks

[Mook]

Have you tried pulling up one door at a time to see if the other would then close on its own? Try both doors, one at a time.

I just had the same problem, took everything apart turns out it was a bad actuator(which was new). With the engine on and headlight doors open and lights off take one of the hoses off of an actuator, put your finger over the end of the hose to check for vacuum. If your finger is sucked to the hose the other headlight should close. You may have to check all of the hoses, I can't remember which hoses are for open or close. I would guess the bottom hoses would be for closing....but I'm not sure.

I found out the hard way that there are many adjustments to the doors. Dropping doors usually means bad springs. At times I had bent the springs to keep the doors tight.

I maybe able to talk you through over the phone,if you think that will help...PM me your number and I'll see if I can help that way!

Good luck....

[flyboy]

Thanks Mook. When I get to it again I will let you know.

[nh68gto]

Your carb may not have enough vacuum. I put a tee on direct manifold vacuum for lights and other items.

Mook is right, Drooping doors is usually a spring and adjustment issue. if actuators are good then the system is not hard to get right. A slightest bit of adjustment goes along way. The end of the springs and arms for the doors.

[David Jones]

My guess would also be the switch. But its only a guess and I have no idea how to check it.

[flyboy]

didnt think of trying an alternate vacuum source. think I will give that a try. Thanks

[Joel Koontz]

Could be a combination of factors.

If one of the "up diaphrams" is bad it creates a vacuum leak. That will prevent that headlight from closing. It may or may not prevent the other one from closing. If you have good vacuum the other one may still close, but slowly. If weak vacuum, it may not close either.

Could be a leak in the line from the switch that goes to the "up diaphram" or could be a bad switch.

There will be a T in the hose to the "up diaphrams". You can pull the supply hose (from engine/tank) and check for vacuum on that line. You could also hook up a MitiVac to that T and see if the the "up diaphrams" hold vacuum. Then use vacuum/MitiVac to test each diaphram individually.

I have found that the original diaphrams are VASTLY superior to most of the aftermarket diapharams. About 10-15 years ago I had a center diaphram go bad and had to replace the actuator. I figured the other side was probably not too far behind and I almost replaced both of them at the same time. Glad I waited, as I had to replace the diaphrams on the replacement actuator 2X before my original (or replaced decades ago) diaphram finally failed. From my experience, if you get 5 years out of a repo diaphram, that doing pretty good.

I have now converted to an electronic setup. It was quite a bit of work/fabrication, but seems to work very well.

[BB1968]

I know you probably want to keep your original, however I worked with mine for several months replacing everything I could find with no luck, then I found a thread on here that showed me how to convert to electric and do away with vacuum. Best move I have made. Open and close great and no drooping. If you decide to go that way you can pm me and I have the diagrams or you can try searching for them. Good luck. PS Nice ride.

[flyboy]

Originally Posted by BB1968

I know you probably want to keep your original, however I worked with mine for several months replacing everything I could find with no luck, then I found a thread on here that showed me how to convert to electric and do away with vacuum. Best move I have made. Open and close great and no drooping. If you decide to go that way you can pm me and I have the diagrams or you can try searching for them. Good luck. PS Nice ride.

Where did you find your kit? And thanlks for the PS, still working on getting a better pic up there

[Joel Koontz]

I'm not aware of any complete kits that are available for conversion to electronic, but this link will provide info on how I and some others have done it.

http://forums.maxperformanceinc.com/...d.php?t=498889

[robz]

Originally Posted by flyboy

Anyone out there that could advise on how to diagnose hidden headlights on my 69 GTO? Shut the car down with lights on. I pulled the doors up by hand, which I had done a time or two before (I know, stupid and lazy). Now both doors work fine opening, but neither make any attempt at closing. If I close by hand, they start drooping. I have good vacuum out of carb, traced all lines from the headlight switch to the actuators, all of which are relatively new. I doubt both actuators would go at same time, and with both only opening and not closing. I am leaning toward headlight switch, but no idea how to diagnose. Does anyone out there have any suggestions? I hate to start swapping parts to figure it out. Thanks

By forcing them up a few times by hand, you probably have removed the inner seal from one of the two actuators...remove the dust boot from each and you will see...I have repaired alot of these hideaways and once they are fixed, they last and IMO, look better when they open/close than any electric version, as I like the delay in each (that's just my opinion)...If you still want to try and diagnose, here are a few links to threads from here I have, to help you out:

http://forums.maxperformanceinc.com/...light=hideaway

http://forums.maxperformanceinc.com/...light=hideaway

[GTO JOHN]

On my car if I shut the car off with the lights on the doors stay open. If I start the car up then they will close when engine is running. Now I shut the lights off and wait about 5 seconds before turning off the key.

[PaulatFast]

Robz has the answer. The electric conversions are for quitters! That factory system is reliable and easy to fix.

[robz]

Originally Posted by GTO JOHN

On my car if I shut the car off with the lights on the doors stay open. If I start the car up then they will close when engine is running. Now I shut the lights off and wait about 5 seconds before turning off the key.

John, you have some sort of leak in your vacuum system (or no check valve), as the canister under driver's side fender, should hold enough vacuum after engine shuts off to close bothe sides fully....

[GTOBOB]

FWIW, I just fixed a similar problem on my recently-finished project. It was the old switch.
1) Start the engine.
2) Turn off the headlights.
3) Swap the upper and lower hoses on one of the actuators. That door should travel to the opposite position. (If not, you've got a vacuum source problem, mechanical interference, or that actuator is bad.)
4) Turn on the headlights. If the doors don't move, you've got a bad switch.

[north]

My experience is that often the problem is a mix of a bunch of things, like many people mentioned the repro upper seals on the actuators are junk, half the thickness of the originals. What helps is to rub axle grease on them and the shafts. It will help them seal tighter and prevents them from popping off.

The most common cause of the lights failing to close after shutdown (but working well during engine operation) is the checkvalve at the vacuum source near the carb being defective, installed backwards or missing in action.

When I buy a GTO with this system I usually spend a day tweaking the system starting at the carb and working down the whole system, hoses, fittings, switch, etc.

Often there are many small leaks; dried out or cracked hose at connections, rust holes in the can or the actuators, leaks inside the switch, cut or melted spots on the hoses, nonstock connections with other vacuum accessories like AC or cruise.

Alignment issues or drooping is often related to wear on the springs and the breakage of the main rod bushing, both tend to let the doors sag a bit when closed and parked.