I have a 69 coupe that has inoperative wipers. Vacuum operated wiper door
opens only to about halfway raised position, and it does so fairly slowly,
then stops. Since wiper door doesn't fully open, wipers will not operate.

Does anybody have a lead on any tech writeups or other advice on best way to
diagnose this problem? I sure appreciate your help!

I don't know if your problem still exists or if anyone has attempted to assist you. Those early C-3 wiper systems can be a pain so start simple and cheap. First determine if all the lines are properly connected and then if the doors aren't catching on something. See if you have the vacuum tank on the driver's side inner fender and check for leaks and holes. Replace the two in-line valves--one is plastic with one port on one side and two ports on the other and the other is a pewter colored valve. These are located in the vacuum line system coming from the tank. If all this fails to correct the problem then it could be either or both the relay mounted on the firewall driver's side or the switch under the doors on the passenger side. If it's the actuator on the passenger's side than that's about $90 new.
Or buy a $4.00 squeegie from an auto parts store.


Scott S.
'70 LS-5 convertible

Send me a fax number to my e-mail and I'll fax you the trouble shooting guide. My work e-mail is MFRANKEN@travelers.com

Mark

The wiper door on "The Toy" has been operating a touch on the sssllloooowwww side for a while now. I usually need to reach around the windshield pillar and give it a nudge to get it to the fully extended position, then the wipers work fine. When turning the wipers off retracting to the closed position seems to work fine. I'll be tackling the vacuum system next spring to try and track down any weak links.

Well guys, wiper door opening problem now fixed. Required cleaning of wiper door solenoid internal parts. See attached site, excellent article, easy repair!

http://www.71corvette.com/wiper.html

Clickable version of above link:
http://www.71corvette.com/wiper.html