dave2007

I was having problems with door closing on passenger wiper. I also had hard time with the AIM pictures. Took me some time just to think what they meant about 1" below stop. Finally , I loosened both sets of adjusting screws, the ones that hold rods to ***** of trans. I set the drivers side on stop (tightened 2 drivers side screws) and then I lifted passenger wiper up and over the stop (I pulled it so far out that I was at least 2" below stop maybe more. This set the passenger side adjusting screws as far as they could go. I then lifted passenger back up and over the stop to rest against driver wiper. It worked but the wipers hit each other in middle of sweep. I fixed that by adjusting screw A on drivers wiper. After all that I set passenger wiper safety switch to close when arm comes down. I now have working wiper door open and close. I am still new to C3"s so forgive me if I explained to much. Also thanks to all the threads that address this issue.

Alan 71

Hi l,
2 things I notice:
There's a bend in the arm that you see in the picture that shows the arm from the side. The arm should be parallel to the glass the whole way to the blade connection.
The vacuum switch is a replacement (white plunger is the give away). Is it possible the replacement's holes don't have as much adjustment as the originals?
Regards,
Alan

This one (you should be copying the IMG code the last one.)

lsolger

Thanks Dave & Alan

The wiper procedue in in AIM is not very clear. Thanks for the tips, I will try in am tomorrow.

Alan- I looked at old switch ( I keep every old part I remove for reference or ?) Holes line up perfectly w/replacement switch. I wondered about that too. Thanks also for the photo posting info.

BBCorv70

The arm looks like it was bent. I'd guess someone may have had a replacement wiper holder on there at one time? The original wiper arms will not fit when using a replacement wiper holder unless they are bent. It would make sense that someone may have bent the arm to get the replacement holder to fit. This raises the wiper arm relative to the windshield. I had a similar issue last fall. Ended up buying new arms and blade holders.

So far as the vacuum switch goes. I have a replacement in my 70 which provided ample adjustment. The adjustment didn't come from slots on the switch, it came from slots in the bracket. There are a few clip nuts on the bracket which can be shifted up or down.

Alan 71

Hi l,
YES! BB is right. Look how long the blade is compared to the holder. Is this the cause?
Regards,
Alan

Original blade, holder, arm.

0Willcox Corvette

Hi Alan:

Been gone a few days. Yes... I've been wanting to do this for a while to today I pulled the lower cover off a wiper arm and took some pictures.

Below shows the function of the mysterious Screw A. Now let me look at the rest of this thread to see what I've missed.

Alan 71

Hi Ernie,
That picture is a real keeper.
I've never seen the inside of the arm... a little more complicated than I thought.
NOW I see how it adjusts the 'sweep'!
Regards,
Alan

0Willcox Corvette

Alan-

Most people don't even realize the screw is there.

Alan 71

Hi Ernie,
People complain about the AIM being so complicated.... and it is.... but there really is a lot of information in those pages! Including 'screw A'.
Regards,
Alan

azza2u

Best pic ever! I had always wondered if that screw adjusted things (the wiper related pages of my AIM are missing). Will be adjusting tonight to hopefully finally get the 68 drivers arm to miss the windshield post!

Thanks.

0Willcox Corvette

I may start a thread on Screw A..... with the new picture it may save some grief...

lsolger

I thought recent suggestions would solve my problem but still no luck. I have noticed that problem seem to be wipers stopping then door comes down on top of pass wiper. I have adjusted, re adjusted....... linkage per AIM and previous posts but wipers still stop before door comes down. The driver wiper stops about 1/2" above bracket and pass side arm is struck by the top rib of the wiper door. I have also tried adjusting the wiper switch on firewall but no luck. Perhaps I do not understand the vacuum/electrical interface of wiper motor shutoff/ door vacuum. I have not lengthened the bolt holes of the wiper safety switch yet and I do not know if this would resolve the wiper position at shut off problem. Any ideas?

Red Vert 02

It sounds to me like the vacuum system is working as it should. The wipers park and then the door closes. The purpose of the vacuum switch is to prevent the door from closing until the wipers park. The problem has to be in the wiper adjustment. Could the vacuum switch be preventing the wipers from parking all the way down ? When fully parked the passenger wiper arm only has to depress the vacuum switch 1/2 way for it to operate. Adjust the wiper arms to fully park, then adjust the switch to be depressed 1/2 way. Did you pull the wiper arm off and straighten it ? Good luck. Are these cars fun to wrk on or what ?

Alan 71

Hi RV02,
Mostly...."or what"!
Regards,
Alan

0Willcox Corvette

The windshield wiper motor limit switch cuts off power to the wiper motor when the switch is collapsed. But.. the door is controlled by the vacuum valve under the passenger side wiper arm that shuts the door...

So you have two things going on right now....

For the wiper door to shut, the valve under the arm must be compressed. For the wipers to stop working the plunger that hits the limit switch must also be depressed.

I looked at your pictures... and the passenger side arm seems to be bent, did they also bend it in a lateral position?

For what you state, the plunger had to be closed to shut the door and the plunger has to be closed to shut off.. so, I'm putting my money on adjustment, a bent arm or.. bad transmissions.. you'll have to take a closer look.

Did you ever get the arms to adjust out per the instruction sheet? If not then I'm sure something is bent and this could include the transmission levers from the motor bell crank to the arm shaft.

Food for thought for sure...

Willcox Inc.

72 corvette roadster

Just a quick note to add to the discussion...I have noticed that it is very hard to find "wiper inserts" anymore in the normal stores. I have also noticed that many of the new wiper blades sold have a higher profile that the originals, which could lead to some door interference if the wiper blade/frame profile is too high. Any thoughts?

azza2u

If the door is adjusted right there shouldn't be any interference as there should still be a reasonable gap above the wiper. That said, I had aftermarket blades and they sat a good 1/4" taller than the original/repros I have on there now and they just cleared the door.

Azza

PhilaScott

been there, done that.
You need to adjust the linkage on the arms that push/pull the arms.
One arm closes a hair quicker than the other .

Read the willcox adjustment procedure.

I had THE SAME issue. If the arms are correct, you can adjust this to work.