Anyone have a service manual detail of the vacume diagram for the Superbirds lights? I have never worked on one and I am going over this afternoon to help a friend fix his. They remain in the open postion even after the car is shut off.
I am guessing it is either the headlight vacume motor or the switch but it sure would make the process go quicker if I had a diagram. I do not have a service manual for the 70 plymouth. I have 68 and 69 but not 70.
Thanks

I cant supply you with anything to view but I can tell you the lights are not opened/closed with a motor. They work off manifold vacuum that keeps them closed while the engine is running and a reserve can that holds vacuum to keep them closed while the engine is off(located under the battery tray). If they close while the car is running but creep up when the engine is off then you have a vacuum leak.
I would start under the dash and look for issues with the vacuum tubing all the way up to the headlight door acutuators.

Sorry about not having any documnets. The information your looking for is not in the FSM anyway. You will need the Superbird supplemental that has all the specific parts and even then it wont tell you about any functioning troubleshooting. My book is at the shop working on my car.

Not from FSM, but...

Should be the same as 68/69 Charger...

Thanks to all for the help. I got them working with replacing some of the hoses. They still have a slow, slow slow leak down after shutting off the car. I will be checking the canister next but I am afraid it is the switch since it is so slow.

make sure to put some grease where the hoses connect to the back of the switch, it'll help with sealing issues between the plastic switch and the rubber hoses.

If they leak down and the hoses and diaphragm in the actuators are good your problem is with the vacuum switch attached to the headlight switch.The grease in the switch dries up,in the summer mine stay shut for months,in the winter about two weeks and they start to open.

Those of us who cheat take the spring off of the side of the headlight pod. The spring is a failsafe. The headlight will work fine without them, and stay closed all of the time.