Popup Headlights opens after engine is shut off

Hey, after i checked my 1969 Cougar when it rolls from the trailer i recognized that the pre owner blocked the popup headlights with pieces of wood.

I found out the reason: The pop up headlights open and close when the engin runs when i switch on and off the lights, everything looks normal.

But when i stop the engine the closed headlights opens very slow. No matter if light is on or off.

Any ideas whats the problem is?

Your car has a vacuum leak, that could be in multiple places, check valve, H/L switch vac. canister under fender. vac. motor,
and every place where the hoses connect. You will need a mighty vac and a lot of patience.

As stated above vacuum keeps the doors closed. So when the engine is off you are loosing vacuum and the doors are opening. Finding the leak just takes time. Good luck.

Mine do the same and its never really bothered me to be honest. I know it could get worse and then I will investigate but I did wonder if there is an advantage in not having the doors continually under pressure?

Guten tag and welcome to the forum and Cougar family. I lived in Zweibrucken for 4 years. Are you military over there or a German national? I love that country for so many reasons! My 69 headlights do the same thing. Like stated above, it is a vacuum leak somewhere in the system. There is an electrical conversion that will replace the old vacuum system and never have to worry about leaks again. A lot of owners on here have done the conversion, as I am going to as well. There is also a video that WCCC has put together on the conversion. Good luck and send some pics sometime.

The thing about vacuum leaks is, if your doors open soon after shutting off engine, then you have a pretty large leak which not only affects the headlights, but could cause poor operation of the engine.

Mine start to open about 10-15 seconds after I shut the car off.

Hey guys, thanks for your answers. Checked the system and found two leaks. One was at this broken shutdown valve.

I bridged it but after that i found another leak. It seams like the balloon or whatever is in that big can of the vacuum motor is broken.

No i have two options. Buy a used vacuum motor on ebay (which cost about 50$ + 35$ Shipping + taxes) or switch to electrical system. I’ll try to find a vacuum motor in germany, do you guys know if motors from other car models with the same vacuum technik also fits to my 1996 Cougar?


PS: @69XRRR7, Nope, life in Germany all my live. But spend many time on US Military Bases like Schweinfurth and Ramstein als well.

Madbutphat, there are a couple of guys who have put “Green Slime” in their canisters and have had success in stopping the vacuum leaks in there. Green Slime is a liquid tire repair that you put in a leaking tire to stop a leak. I have no idea if it is available in Germany. Got to believe there is some product that is the same. There is at least one thread here or on the other forum about using this stuff.

On another note, are you aware that there is a Cougar Club in Germany?