Need to check windshield wiper motor and relay for possible replacement

[tshih]

Anyone can point me to a DIY procedure to change out the wiper motor or relay is much appreciated. I have a 1988 carrera with slow response wipers which makes grinding noises from the fresh air vent area in the front trunk. Does one have to remove the cardboard under the carpet blocking access to the fresh air ducts blocking the wiper motor? Also my car has A/C so there appears to be more air ducts than the factory workshop manual shows. Does anyone have experience with replacing the motor in A/C equipped 1988 carreras?

Tom

[spuggy]

Originally Posted by tshih

Anyone can point me to a DIY procedure to change out the wiper motor or relay is much appreciated.

Haven't seen one, hopefully someone will post one.

I have a 1988 carrera with slow response wipers which makes grinding noises from the fresh air vent area in the front trunk. Does one have to remove the cardboard under the carpet blocking access to the fresh air ducts blocking the wiper motor?

At a minimum, I think you need to remove not only the fiberboard cover, but also the fresh air blower. You can disconnect the hoses, leave the cables connected and swing it out of the way. Wiper relay is right there once you do that, wiper motor off to your right a bit. You'll need a second person to get the relay screw started when you replace it...

It's kind of cramped. Put something soft in the trunk, you'll be kneeling or lying in it for a while.

[86 911 Targa]

Originally Posted by tshih

Anyone can point me to a DIY procedure to change out the wiper motor or relay is much appreciated. I have a 1988 carrera with slow response wipers which makes grinding noises from the fresh air vent area in the front trunk. Does one have to remove the cardboard under the carpet blocking access to the fresh air ducts blocking the wiper motor? Also my car has A/C so there appears to be more air ducts than the factory workshop manual shows. Does anyone have experience with replacing the motor in A/C equipped 1988 carreras?

Tom

Tom,

According to the Bentley, page 920-3/4, a lot of items must be removed, including the fresh air blower assembly.

Here is a jpg on what might be the wiper relay.

It is identified as the windshield washer relay.

You may pm me as needed.

Good luck,

Gerry

[spuggy]

Originally Posted by 86 911 Targa

According to the Bentley, page 920-3/4, a lot of items must be removed, including the fresh air blower assembly.

That's all you need to move.

Here is a jpg on what might be the wiper relay.

It is identified as the windshield washer relay.

That's the screen wash relay.

The wiper relay he needs is directly behind the fresh air blower, held in place on the dash gap by a sheet metal screw from inside the cabin and can only be reached from the trunk. The wiper motor is also exposed by this procedure.

Search for threads that mention problems with "intermittent wipe", the wiper relay does that as well as regular wipe.

[Zeke]

Does the relay "park" the wipers too? I suspect it does and mine have to be parked by bumping the stalk.

[tshih]

Well I blew the fuse yesterday trying to get the wipers to move. Means there is either a short or the motor is drawing too much current. Anyone know if the motor can be refurbish inexpensively by those who rebuild starters and alternators?

[wwest]

Originally Posted by milt

Does the relay "park" the wipers too? I suspect it does and mine have to be parked by bumping the stalk.

No, the "park" capability is almost always inside the wiper motor worm drive gearbox. Wiper motor has two sources of power, you turn it on and it runs continuously, you turn it off and motor power is maintained internally until the wipers reach the "park" position.

Some wiper motors actually reverse direction when traveling to the park position so the mechanical drive escapement can have a "deep(er)", park position, over-travels the standard "swipe" range.

[RWebb]

you might remove all the washers and seals from the stubs that run the arms -- clean it all out well & re-oil or grease and replace with cleaned or good ones

it is an old 356 trick that is discussed in a Pano article, reprinted in UpFixin' somewhere.

I plan to do this on my 1973.5 too as my wipers seem a bit slow.

[kidrock]

Originally Posted by wwest

No, the "park" capability is almost always inside the wiper motor worm drive gearbox. Wiper motor has two sources of power, you turn it on and it runs continuously, you turn it off and motor power is maintained internally until the wipers reach the "park" position.

Some wiper motors actually reverse direction when traveling to the park position so the mechanical drive escapement can have a "deep(er)", park position, over-travels the standard "swipe" range.

I had a similar issue as Milt, my wipers wouldn't "park" in the correct area unless I "bumped" my stalk. Also, my intermittent wiper button was skittish and inconsistent. I replaced my stalk, and all the issues disappeared.

Tshih...try this to get access to your motor.

(1) Remove the fresh air blower (disconnecting air hoses from blower end only).
(2) Remove the "Y" pipe from the A/C piping and the two associated air hoses. This unit sits in front of the fresh air plenum and is held down with a single phillips screw in front.
(3) Remove the fresh air plenum by removing the intake grill. After removing the two retainer screws under the intake grill the plenum can be "wiggled" out.
(4) Remove A/C piping to center duct. This unit simply slides on/off the back of the duct.

[tshih]

Thanks kidrock,
I did what you suggested and am posting the photos of each step. The wiper relay I assume is the one in the center with the white labeling SWP and a bunch of numbers 911.XXX.XXX,XX. Now the question is how to test the relay and how does the wiper motor dismount?

[tshih]

I assume the circuit diagram photo I posted has the wiper relay labeled as "wipe intermittent action control " in upper right portion of photo (device with 7 wires same as plug in photo in front of wiper motor (black cylinder with aluminum bladed wheel). Someone please direct me on how to check the relay with a VOM. And of course the motor.

[tshih]

Well , I only got 11.9V checking potential across the red and brown wire with the wiper switch turned to 1st position. The motor is getting very hot as the wiper arms slowly moves back and forth. Does this mean the motor is getting shorted internally somewhere? Also, I believe the motor comes out still attached to the wiper mechanism

[kidrock]

tshih,

I'd taken out all this garbage recently to gain access to the back of my (now operable) cigar lighter. It was due to all that work that I accidentally figured out that you could also gain access to your wiper motor, too.

I'm horrible at figuring out electrical ghosts, but even a blind squirrel has to find a nut once in awhile.

Me? I'd stick a known good relay in there and see if it makes a difference to your motor. I'm not sure, but I believe that:
1) either a relay works, or
2) it don't.

11.9 volts sounds like it'd be enough to make the motor work, but the fact that it gets really warm and runs slowly tells me that your motor might likely be shot...hopefully one of the experts will call my B.S. on this (wait for it).

By the way, the arms don't come off with the motor. Don't forget to remove the wipers before you start removing the rest of the stuff.

Hope this helps.

[tshih]

Thanks,
got the sucker off and looking for replacement motor at lowest price.

[tshih]

Closing out this thread. Found used motor for $89 shipped. Installed and wipers work great. Now probably needs new switch which was purchased new.

Thanks for all the useful advice posted here, guys.

Tom

[kidrock]

awesome, Tom....it's always a great feeling when you accomplish something successfully and cheaply.

[NYNick]

Just discovered this old thread. Will be doing this job soon and will update results. I got as far as not being able to wiggle out the fresh air plenum. Sure will be easier to get to the motor if I can get that plenum out.

Nick

[NYNick]

It's out! A little wrestling and the fresh air plenum is out, exposing the windshield wiper motor. May be able to get to the nuts from here, but either way at least the motor will be easier to take out from the frunk than through the gauges!