69 wiper door issues

[Mark B.]

Guys, When I start the car the wiper door opens and then closes. What now happens is when the car shuts off, and a few minutes go by, the wiper door opens again. The wiper door is off as changed the winshield. I can see the one rod go vertical where the wiper door would mount too. Any thoughts?

Mark

[Patrick H.]

Re: 69 wiper door issues

Vacuum leak somewhere in the system.
Your job is now to play detective and figure out where.

Doc Rebuild has a testing guide if you wish to order it, or there might be online troubleshooting guides.

[Mark E.]

Re: 69 wiper door issues

A common cause of the wiper door opening then closing during start up is the check valve.

A good way to check the vacuum system's integrity to connect a vacuum pump and gauge to the supply hose that normally attaches to the intake manifold. Use a long vacuum line to locate the pump away from the car (outside the garage works well). The idea is to energize the vacuum system with the pump without noise from a running engine or pump so you can hear vacuum leaks. Test operation by opening/closing all switches (headlight, wiper, bypass switches under dash).

Another test is to draw the system down to 15" or so, turn off the pump, and see how well the system retains vacuum. Clamp off sections of hose to isolate and locate leaks.

[Edward J.]

Re: 69 wiper door issues

Mark B. I had the same problem with my 72 and I found that the vacuum switch under the wiper grills on the pass. side was the issue, on my switch the plunger was broken internally, I took it the boot off and the shaft was broken on the inside, and you could not see it by looking at the switch from outside the car. Just a warning these switches are reproduced and are not built very well, they have leak problems buy yourself a couple. I would also as the everyone is saying do some testing to look for a vacuum leak first the smaller hoses first, if you still have the original hoses, look at the hoses where they slide overall the fittings, if they are lose at the fitting you can sometimes cut off a 1/2 to3/4 inch's off and get a tighter fit. Good luck

[Anthony F.]

Re: 69 wiper door issues

Mark, I was reviewing past posts and noticed yours.

In case you haven't gotten this sorted out: I had the same problem occur on my 72. Check under the boot for the wiper door actuator. The seal may have been pulled out of the actuator. It's happened to me at least twice in the past 46 years, and only takes about 10 seconds to check.

vacuum can.pdf