Crazy windshield wipers

[pope]

Since I bought my car a couple months back, the wipers have been acting weird.

On the normal and fast settings they work well but when I switch them off, they do not return to 'home' position. I have to switch them of at the right moment.

On the intermittent setting, they act very weird. First of all, they move with the high speed. Then there are times when they don't move for a few seconds then they start. Other times while they are moving (fast) they all of a sudden stop. Weird stuff also happens when I use the washer function.

What could be the problem?

[1982911SCTarga]

Your symptoms sound like there's a bit of dirt or corrosion on the contacts of your windshield wiper stalk switch. This can cause erratic wiper action like you've described (and affecting the intermittent wiper control). You can carefully take apart the steering column trim pieces and again -- carefully -- clean the contacts. Start there and see if that resolves your problem.

Brian

[pope]

Cool! I'll try that quite quickly since I've already removed the steering wheel and the switches are out there in plain view. I'll give an update later tonight after I get home.

[PCA7GGR]

The ’70-’71 wiper motor wiring is differrent from other years. Pull your clock out and make sure that the wiring to the motor are in the right order:
Black/Yellow
I
Red --- --- Brown/Grey
I
Black/Lavender
__
Brown

Mine were wrong. The low (intermittent) posiiton did not work, middle (low speed) and hihg (high speed) switch positions worked but the wipers would not park to their rest position. Correcting the woring order cured the problem. The system also has two unique relays as well.

Like you I posted the problem on Pelican and Andrew15 (Canada) provided the correct wiring diagram.

[billwagnon]

That is by design. You have to park them manually, just like on a Ferrari.

[DByers]

Sergio, Do you still have that schematic or link to the thread? I did a search but could not find it.
Thanks

[Goth]

I had a similar problem with my 84 Carrera. The wiper switch has copper arms with the contacts on the ends. These arms get bent over time and need a little tweak. Look at how the wiper switch operates. You will see that when you move the lever, it makes some contacts close while others may open. The contacts are pretty easy to spot and adjust, as they are like the ones you would find in many relays (looks like point type on flexible copper arm). You can bend the copper arm so the contact is in the correct position.

Hope This Helps..

EDIT: I may have cleaned the contacts as well (as Brian suggested).

[pope]

I checked the switch last night but it looked ok. All contacts looked to be working fine and I tried cleaning them a bit but in the end the result was exactly the same.

I'll check the wiring tonight to see if it's been tampered with.

[pope]

BTW, here's that thread:
http://forums.pelicanparts.com/showthread.php?t=194934

[PCA7GGR]

Sorry, but I never did find a schematic that was specific to our year.

The ones I did find for other years had a blue wire which our year did not have. The following is my crude attempt to show the wiring at the motor. If you pull the clock out, you should be able to see the wiper motor and the five wires to te wmotor. Four wires are grouped in a diamond shapes and the brown ground wire aloe below the the four

.....Black/Yellow
...........I
Red -........- Brown/Grey
...........I
....Black/Lavender
_
Brown

Start at the motor. If the wires are not in this order, the wiper stalk will not correspond correctly to the wiper motor.

[pope]

Sergio, you're the man!

I pulled out the clock and I beheld the wiper motor wiring.



I rummaged around under the dash and found a red wire. It was on a capacitor of some sort. The other side of the capacitor went to the stereo. I pulled that off and replaced the brown wire on the motor and voila! It is now working!

Intermittent is 2 fast wipes and then pause. Normal is continuous slow. Fast is continuous fast. Switching off after any of the 3 settings now parks the wipers in the 'home' position.

Yaaaay!

I unfortunately blew a fuse though. I guess it's because I didn't replace the red wire on the capacitor.

[RWebb]

Huh - so a 1970 _does_ have an intermittent speed? (= 2 fast wipes then slow)

I never knew that. My '73 and '75 did not have intermittent.

[PCA7GGR]

Cool! I hear the relays are NLA and hard to find. You are fortunate, like me, that they are still operational.

Yeap, the '70-'71s 911 wiper system was ahead of it's time. So much so, that Dr. Porsche decided to delete it for a few years until they went to the intermittent switch on the dash.

[andrew15]

It sounds like the problem is fixed, but I thought I'd add that the 1970 specific wiring diagram is 'SL35' as found in the factory workshop manual.

Regards,
Andrew M