1984 944 wiper motor stopped working

[Obin Robinson]

i noticed over the past few days that the wiper motor on our 1984 944 was a little noisy. this morning, it won't work at all. i can hear the relay going "clunk" whenever i turn the wipers on, but of course the motor doesn't move the wipers at all.

is there a good quick-and-dirty test to see if the motor itself is dead? the voltages going to the pins should be 12V right?

thanks!

obin

[SoCal Driver]

Later wiper motors will work on the early cars with a few modifications. Have to use the plug off of the older motor and switch a few wires. Can't use the three speeds. Just two of them. Also have to notch a couple of the reinforcing ribs to clear the older mounting bracket.

[Obin Robinson]

cool thanks! will the intermittent setting still work on the motor? or will it now only be a "2 speed". also is there a way of testing this motor to be certain that it's shot? from what i can see there are several of the points on the motor that are showing continuity. logic tells me that the motor is shot, but these are German electrical components so as we all know logic is always the first casualty!

thanks!

obin

[anotherblack944]

Just a thought.. A few years ago mine did the same thing (noise and stopped working that is) on my 84. Only, with mine I could hear the motor spinning but the wipers wouldn't move. I pulled it and opened the cover where the wiper arm connects. There is a large fiber gear in there that the teeth had stripped off of. They were scattered all over inside the housing. I'm thinking you may have had the same thing happen. Possibly one of the broken teeth is jamming the drive motor.

The gear is not a replaceable part. It required a whole new motor assembly.

[Obin Robinson]

last night we went to Advance Auto Parts and ordered a new/remanufactured wiper motor. it was only $80 + core charge. it's coming in today so i'll go and replace it after work. any hints as to make extraction and installation easier?

thanks!

obin

[anotherblack944]

Nah, pretty trivial as I remember. Just went and looked but there is a plastic cover over it so I couldn't see for sure.

1 Phillips screw and the cover comes off, take off arm pivot, and (I think) there are 2 bolts that hold the motor in, slide it to one side, unplug connector and it lifts right out. Was a little tougher to get it to slide back in but you just have to get the right angle.

Oh, and be sure to note the position of the arm pivot before you remove it. (if not it's still pretty easy to figure it out).

[SoCal Driver]

Leave the arm off of the motor and run it a bit. Turn the wipers off and the motor will "park". Now align the wipers on the windsheild in the parked possition and attach the arm to the wiper motor.

Alternately you can assemble the motor to the cross bar and arms, install it, run the motor and park it, then attach the wiper arms on the piviots.

Intermintent wipers is the wiper relay not the wiper motor. The speeds are motor windings and selected by the contacts in the wiper arm switch.

While you have the wiper cross bar out it's best to lube the heck out of the piviots. You may have to disassemble them.

[Obin Robinson]

what do you recommend for wiper arm lube? lithium grease? moly grease? silicone grease?

thanks!

obin

[SoCal Driver]

Think the last time I took apart the pivots it was a light yellow translucent grease. Mostly dried out. Think long term water proof.

I use the Bosch ignition point lube for many things other than wheel bearings. Comes in a tube.

[Obin Robinson]

damn! i got the replacement motor and i've blown 3 fuses trying to get it to work. it is the exact replacement part as far as I can tell: same case, made in Germany, etc. the ONLY thing i can see that's different is that the resistance measurements are different on this "new" motor from the original wiper motor.

offhand, for ease of identification, with your wiper motor mounted here will be where the terminals are located:

center - center of the "clock face"
53B/i - straight "up" / 12 o'clock
31b - to the front of the car / 3 o'clock
53 - parallel with the ground / 6 o'clock
53a - to the back of the car / 9 o'clock

here's what I have from my original motor:
center: motor ground
53: green wire coming from motor
53b/i: red wire coming from motor
31b: white wire coming from motor

terminals:

center - 53: 190 ohms
center- 53b/i: 1.4 k ohms
center - 31b: continuity
center - 53a: 2.3 k ohms (and rising)
53 - 53b/i: 1.8k ohms

and here's the replacement motor:

center - 53: 3.3 ohms
center - 53b/i: 63 ohms
center - 31b: continuity
center - 53a: infinite / no measurement
53 - 53b/i: continuity

my troubleshooting tells me that something is probably shorted in the motor i got. doh!!!! i mean shouldn't the resistance between the red and green wires that come out of the motor be higher than continuity?

does anyone have a multimeter and they can confirm these measurements for me with their working motor? should i bring this one back? i need a working wiper motor asap and i can't waste the time with the car sitting at a garage with them basically doing the same thing I am.

another question is that how can i test to see if it's really the relay that's bad?

thanks!

obin

[SoCal Driver]

31 (br) is ground.

53 (gn-bk) and 53b (gn-ye) are the two speeds.

You should be able to run the motor directly with jumpers from the battery using these connections.

31b (gn) and 53a (bk-gr) are used to park the wipers.

31 does make intermintent contact with the parking tracks. These tracks and their wipers can become gunked up and cause problems usually in parking the wipers. Other problems are the relay and the wiper switch assembly on the column.

[Obin Robinson]

thanks!

last night i plugged only the original wiper motor in but didn't attach the arm. i turned the key to ACC and then turned the switch on. i heard the relay go "clunk" and then saw the motor do a slight wiggle then it stopped. the motor didn't spin at all. i did measure the plug without the motor started and i did get voltage out of it so i guess that means that the relay is functioning right?

like i said before, the motor made a bit of noise before it stopped running, so i am guessing that the motor itself is dead and this is NOT a problem with the relay or switch. is there a specific test i can do to the plug without the motor connected that will tell me if the intermittent part of the wiper control is working properly?

so far does it sound like the rebuilt replacement motor i got was just defective (or the wrong part)?

thanks again for your help! it's greatly appreciated.

obin

[SoCal Driver]

Take the cover off of the original motor and inspect the gear.

[Obin Robinson]

ok, will do. you think it might be worn or broken? there's no replacement for that other than a new motor right?

thanks!

obin

[SoCal Driver]

New motor. Or used. Just curious as to the failure mode.

A replacement motor should have been plug and play. Don't know why yours blows the fuse other than a bad column switch. Or wiring.

[Obin Robinson]

Would bad wiring cause the original motor to make a loud noise before it failed?

obin

[SoCal Driver]

Growling from the wiper motor is because it was flooded. That is the drains in the front don't. Messes the whole thing up bad. Did my original. Took it apart a few times, cleaned it up and lubed it. Finally was dragging so slow it reminded me of the vacuum system on the 55 Chevy I had. Never had a bang or any loud noise.

[SoCal Driver]

If the gear is busted in the original check the piviots. These could be binding or frozen. Take the arm off of the motor and bend the wiper arms out straight against their springs. See if you can rotate them with out any drag.

[Obin Robinson]

yeah that's one more thing i just remebered now... the drain was plugged badly and the entire motor was underwater during a downpour. it didn't work right after that and that's when the problems started. still sound like the motor is messed up or could it still be wiring?

thanks!

obin