lsolger

I recently replaced the wiper safety switch. Wipers function well but when turned off the door closes on top of the passenger wiper arm where it bends down toward glass. The transmission link cannot be adjusted further and the switch is as far down as it can go on the bracket. What could cause the door to close prematurely?

Easy Mike

Sounds like your new switch is letting the door close too early.

lsolger

is there a diagnostic procedure to test wiper safety switch? thanks

Alan 71

Hi l,
There is a test procedure, but just to test the operation of the inter-lock switch. It just tests that the plunger opens and closes the port sending the vacuum to the relay. It sounds like yours works, but it's opening too soon.
I think the only cure is to move the switch away from the wiper arm. Can the holes in the mounting bracket be elongated a bit to accomplish that?
I realize that's not curing the cause, just the symptom.
Happy New Year!
Regards,
Alan

0Willcox Corvette

The switch holes can be elongated.. but you may want to adjust the actual wiper arms before doing anything.

Corvette Windshield Wiper Arm Adjustment Procedure 68-72

Year: 1968-1972
http://willcoxcorvette.com/repairand...elp.php?hID=98
Wiper Arm Adjustment Procedure 68-72. Learn how the arms were set at the factory with this help guide.

Alan 71

Hi W,
I thought from l's post he had already done that when he mentioned adjusting the linkage.
Maybe not?
Regards,
Alan

lsolger

thanks for input!! Not sure if this is related to my door issue but the left wiper toe hits the middle of the stop park bracket and thus is not 1" below the stop bracket as shown in the assembly manual. I think the wiper arms are 'keyed' to the transmission shaft and I think I can rule out arm not on shaft right.

0Willcox Corvette

Hi Alan-

There are two adjustments. The transmission levers at the bell-crank and the actual arm tilt on the wiper arm. In his original post he stated that he adjusted the transmission link but didn't say anything about the arm tilt. It is my guess that the wiper arm is hitting the shut off vacuum relay before the blades are under the door and a simple adjustment may be all that is needed.

Another thought is that the actual linkage arm may be bent...

Not sure if this is related to my door issue but the left wiper toe hits the middle of the stop park bracket and thus is not 1" below the stop bracket as shown in the assembly manual. I think the wiper arms are 'keyed' to the transmission shaft and I think I can rule out arm not on shaft right.

When you do the transmission adjustment you put the arm and blade under the stop and tighten. When finished, you pull the arm over the stop and let it rest on the stop. It will feel tight on the stop but it should be correct. Then adjust the tilt of the blade with Screw A.

Alan 71

Hi Willcox,
I can remember a few times in my life when people have decided to "SCREW A"!
Regards,
Alan

I can understand how screw A adjusts the 'sweep', but not the timing of the arm/switch/door.

lsolger

Thanks Wllcox and Alan.

I misundersttod function of the A screw. I thought adjusted length not tilt. I am still puzzled that my left wiper hits middle of stop brkt and I cannot set to 1" below per specs. My stop brkt is 7" (C/L to C/L) from wiper motor favoring the pass side. In A/M it looks like it should be directly behind the motor. I did not see any dimensions however. I am wondering if brkt is mounted wrong that it may cascade into my other problem of door closing on top of rt wiper? Just a thought

Alan 71

Hi l,
I just looked at the AIM, UPC 1, Sheet A13. You're right, the stop APPEARS to be right beind the wiper motor.
But, I measured the position of the stop on my 71 and it's around +- 9" from the wiper motor shaft to the center of the stop; to the right.
I can't imagine that that's your problem since your problem isn't whether the wipers are all the way down, but rather it's WHEN the right side arm hit the safty switch's plunger to send the vacuum signal the door relay.
There are 2 possible adjustments... the bracket to the cowl bolts, and the switch to the bracket. Have you tried both?
Trying, HONEST!
Regards,
Alan

lsolger

Thanks Alan

Just grasping at straws. I have switch all way down on bracket but I have not tried adjusting bracket to cowl. Is there some play here? Will try this next

Alan 71

Hi l,
I really don't remember if the switch bracket moves, or even if moving it will help.
ANY CHANCE it's earlier/later arm of a slightly configuration?
Here's the right-side arm on my 71.
Regards,
Alan

0Willcox Corvette

Alan-

If the arm hits the shut off vacuum switch under it, vacuum is allowed to the relay and the door closes.

But...

If the passenger side blade is tilted upward it can catch the door and prevent it from shutting.

It was just a hunch.

The other things it could be is the linkage for the transmission or a bent wiper arm.

I've never had to elongate a vacuum valve to get it to operate properly.. I've read of others doing this but in most cases anytime the door hits the arms before it is closed it is an issue with one of those items.

Ernie

0Willcox Corvette

On original cars the bracket for the switch nor the switch were adjustable. I'm lost too as to why the problem. Can you post up some pictures?

lsolger

I am new to site and have not posted any pics yet. I will take a couple tomorrow and try to upload here. Thanks for continued input

Alan 71

Hi Ernie,
I don't really understand 'screw A'.
You seem to be saying it pivots the position of the blade relative to the arm?
Is that it?
Regards,
Alan

lsolger

trying to upload photos but apparently I cannot per posting rules? I am new to site. I did not find any control panel options to allow attachments. Any help?

Alan 71

Hi l,
Everyone can post pictures.
You need to upload them to a site like PhotoBucket and then copy the img code of the picture you want to the body of your post. You'll see the code in your post until you click 'preview post', then you'll be able to check the post and picture; if it's what you want, click 'submit reply'.
Regards,
Alan

lsolger

Thanks Alan. Here are photos of wiper/door. I went thru AIM procedure twice yesterday but did not resolve problem. Could wiper arm be bent?

http://s1103.photobucket.com/albums/...t=DSCN1908.jpg

http://s1103.photobucket.com/albums/...tZZhttp%3A%2F%

http://s1103.photobucket.com/albums/...t=DSCN1916.jpg

http://s1103.photobucket.com/albums/...t=DSCN1929.jpg