Windshield Wiper Issue

[NCGermerican]

Hi All. Posting here since this would apply to all 85.5+ 944's, but the car is a 1987 944 S. I've had the car for almost 3 years and the windshield wipers have always acted strange. They work on high speed (let's call it speed 3) and when triggering the windshield washers. However, speed 1 and speed 2 do nothing. When the wipers do work, they will not properly park themselves on the windshield - they stop wherever they are on the windshield at the moment I turn the wipers off.

I've already replaced the entire steering shaft switch module (signals/wipers/cruise) with a brand new genuine unit, but that didn't help. My next thought would be to pull the wiper motor (total pain), but wondering if there is anything else I can try first to see if that solves the issue?

[icb]

I thought I had some info on this type of failure, it really rings a bell. Although I can't find anything written, I remember seeing someone say somewhere that these issues are often traced to a problem with the intermittent wiper relay. Looking at the relevant part of the wiring diagram though, it seems to me that both the speed 1 and 2 issue and the parking problem will either be a wiring fault on the way to the motor or a fault within the motor, like a corroded connection (seeing as you just replaced the control switch).
When the wipers are parking themselves, they get their power from the blk/yel on pin 4 of the wiper motor; it ultimately comes off fuse 24 and is also used for the heated wiper jets. Checking these points for +12 with the key in run would be a good test.
Removing, taking apart and cleaning the wiper motor is certainly within your skill set. I'm planning to do a blog episode about what I did to overhaul my wiper system, but I'm not sure when that's going to happen. Happy hunting!

[NCGermerican]

I thought I had some info on this type of failure, it really rings a bell. Although I can't find anything written, I remember seeing someone say somewhere that these issues are often traced to a problem with the intermittent wiper relay. Looking at the relevant part of the wiring diagram though, it seems to me that both the speed 2 and 3 issue and the parking problem will either be a wiring fault on the way to the motor or a fault within the motor, like a corroded connection (seeing as you just replaced the control switch).
When the wipers are parking themselves, they get their power from the blk/yel on pin 4 of the wiper motor; it ultimately comes off fuse 24 and is also used for the heated wiper jets. Checking these points for +12 with the key in run would be a good test.
Removing, taking apart and cleaning the wiper motor is certainly within your skill set. I'm planning to do a blog episode about what I did to overhaul my wiper system, but I'm not sure when that's going to happen. Happy hunting!

Thanks Ian! I’ll check for 12v. I’ll price out a relay to see what those go for as well. I know this car sat outside for quite awhile at some point in its life so my hunch is I’m going to need to pull the wiper motor. At the very least I’m sure it needs a good cleaning. I’m most worried about cracking the blower cover. It was replaced with the 968 piece at some point and those things are over $200.

[icb]

I know, I replaced mine too. It seems crazy for a piece of vacuum formed plastic but well worth it in terms of the appearance boost. Gently warming it up helps a lot, but it's really easy to distort the original cover with too much heat.

[Tom]

+1 on trying the relay first, and then opening up the motor and cleaning it up (or getting a new one). It has wiper contacts kind of like the horn behind the steering wheel, which can get gummed up and/or just wear out over time....

[944er]

A look at the schematic shows that the intermittent relay is not involved in medium speed operation. I would check for voltage at the motor on medium speed, black with grey stripe wire on pin 5.