self locking driver's door

[Montana Tbird]

A few years back, I replaced all of the vacuum lines in my 65 bird while having the dash reupholstered. Everything seemed to be working ok, but last fall when I'd start the car, the driver's door would lock when the vacuum built up. The passenger door doesn't do this. I rebuilt everything in the drivers door two winters ago, but haven't pulled the door card on the passenger side yet. The dash lock switch doesn't affect either door to lock or unlock either door. I put a vacuum on the largest nozzle in the switch while holding my fingers on the two smaller ones. It would hold a vacuum and release the pressure when I pushing the lever either way. I'm going crazy trying to chase down the issue - it's got to be a vacuum issue, but not sure where to look next. Any suggestions? I'm not ready to unplug them yet, but that may be the easiest solution.

Thanks guys!

[Yadkin]

My car did not come with that option, but the problem has to be one or both of the switches, since they interact with each other.

[Montana Tbird]

When you say "one or both the the switches", are you referring to the locks on the doors, or the one on the dash?

[Yadkin]

Originally Posted by Montana Tbird

When you say "one or both the the switches", are you referring to the locks on the doors, or the one on the dash?

Gosh, there are three? Again, my car doesn't have that option. I retrofitted a electronic system that locks both doors with my key fob.

I am somewhat familiar with the electric versions on later models, since I am currently restoring an '81 Corvette, and that has switches on each door. both switches are tied together so that operating one locks both doors.

I assume that the vacuum system works the same way, any switch locks both doors. So they have to be tied together. Two, three, or four, it doesn't matter, you could have a leak at any of them.

The switch that does my rear panel works perfectly, along with the check valve between it and the source vacuum. The motors I had to replace. I assume that your door lock switches are the same manufacturer and probably built just as well, so maybe just a good cleaning will make them work properly.

[Montana Tbird]

Thanks - I'll open up the door panel in the next week and see what surprises I can find. I'm hoping for a vacuum motor with a disconnected hose! Appreciate the advice.

[Yadkin]

Originally Posted by Montana Tbird

Thanks - I'll open up the door panel in the next week and see what surprises I can find. I'm hoping for a vacuum motor with a disconnected hose! Appreciate the advice.

More likely a rotted hose. I replaced every hose in my car. Ford must have used a bad supplier in '64.

[jdhutch]

there is another valve behind the front of the dash by the fuse block.
Thunderbird ranch at tbirdranch.com has several vacuum line charts that are helpful.

[Yadkin]

I found this diagram. Looks like there is supposed to be only one switch.



The object at the top of the drawing, just left of center, looks to be a simple junction "tree". If that is true then it can be cleaned and tested for leaks, and if broken, replaced with one pass-through and two tees. If there are check valves integral and they are not working, they can be replaced with remote ones.

Once you locate that tree, it should be a simple process to test hoses for leaks and operators for function using a simple hand held vacuum pump.