70 wiper relays

[michael70st]

I am trying to put my wipers back to the correct 1970 spec having put up with bodged up later setup for years on my 70 911

I have fitted the correct one year only 70 motor, 70 switch and both relays 91161511100 and 91161511200.

My wipers run as intermittent wipe, slow and fast as required but only with the follow up relay 91161511100 disconnected and of course then will not park. When on intermittent they wipe part way each go taking 3 turns to get back to the start.

If I connect the follow up relay 91161511100 the wipers run fast all the time even with the switch in the off position.

I have taken apart both relays and tested them. Both appear to work correctly so far as I can tell. 112 cycles correctly and I am sure it's correctly wired. 111 triggers with a live feed to 53a and an earth feed to 31 and T. When connected all the wires trace to where they should be.

The loom although historically butchered is as it should be. The only diagrams I have don't show the 1970 setup well. If anyone can post a correct one that would be welcomed. The one I have is marked 68-72 but does show the relays. This is from the Clymer handbook.

At the motor the two direct feeds to 53 and 53b are fine and trace back to the switch when set the run fine. I have a constant live to 53a as required and 31b traces back to 31b\s at 111.

Can anyone through light on why 111 does not deactivate when the motor turns to the park position. I don't fully understand how the relay is supposed to deactivate at this position. In theory it looks as if, at park the live feed at 53a is isolated by the gap in the contact wheel and terminal 31b connects to earth. However if I run a wire from 31b/s on 111 the realay does deactivate but the wire is arced to earth so it would blow the fuse if wired this way.

How does 31b going to earth deactivate 111 . am I miss understanding something.

[michael70st]

Sorted it..
Grey line to T terminal on switch was running to earth all the time as the contact blade had bent and welded itself to the earth blade inside the switch. This was activating 91161511100 all the time. Now parking between intermittent wipes and when switched to off.

[PMNorris]

I am having similar issues in that my wipers won't park on my 70T. All the other functionality appears to work and I can feel the follow up relay clicking when the intermittent wipe is on, so I am assuming that is working correctly. I believe I should get a 12v current through the grey wire when the switch is at the off position and the ignition is on, but I don't. Can anyone confirm if that is correct?
I'm assuming my issue is the switch. I've tried cleaning all contacts in the switch and relay, but that didn't help.
If anyone has a circuit diagram of the follow up relay that would help too.

I've created my own mini wiring diagram just for the wipers to make my life a bit easier.



Many thanks

Paul

[PMNorris]

I've been doing a bit of research. My next step was to remove the wiper motor, so I removed the clock and speedo to get to the connections.... This is what I found



So, I don't have 53a (the spade connector on the left) connected. This goes straight to the follow on relay. I'm optimistic that this is my problem, but my wife has told me to stop faffing in the garage for today, so I now have a G+T instead of my circuit tester. I will hopefully finish this project tomorrow.

This link describes the wiring on the motor in detail.
http://forums.pelicanparts.com/porsc...-question.html

This link is also useful
https://www.early911sregistry.org/fo...r+motor+wiring

Paul

[PMNorris]

Fixed it. All working now. I made a Youtube video too!!



Paul

[Lz7w]

I'm trying to diagnose a "no park" issue with my wipers as well, and this thread is very helpful! I don't hear the follow up/park relay clicking, so it seems that either it's not getting the right signal or it's dead.
can someone with a better understanding of the relay setup and/or of how to read the wiring diagram for this setup shed some light on how the park relay activates and deactivates? thanks!