[67Twistytee]

Can the motor on the rear defogger be rebuilt? Mine is hooked up with the original switch, power wire and ground wire. It appears to be getting the feed, but no fan action. The unit is dry with no rust. Are these worth taking apart or am I better off trying to source a replacement if the motor is seized?

[indymanjoe]

Hook it up to a battery,direct to the motor.Does the fan blade turn freely? Yes i have to think any decent elec motor shop could rebuild it.

[indymanjoe]

Any pics? I have seen some on e-bay when i was looking for a motor.Py member hooked me up though.

[67Twistytee]

I'll post a few when I take it out. I'm not in the mood to crawl back into the trunk until this cold spell breaks. Guess I've grown soft since moving down south

[Jeff Hamlin]

You can test it in the car if you choose too.
Just need to make long test leads and use a good battery in the trunk.
I would do this before taking it out, and yes you have to climb into the trunk.
Getting in there is the easy part, getting out is the trick
A good auto electric shop may be able to rebuild the motor if needed, or even supply a functional replacement.
While it may not look correct it would fit/function.
EPAY or other online sites are an option, to widen your search remember these were used/offered for most GM models.
Good Luck.

[Satyr1966]

I had one of these on my '66 GTO show car back when I first got the car in 1973. I was just using the car as my daily driver at the time including rain, fog & snow. The thing was so ineffectual that I just stopped using it. When I got my PHS documents & figured out it was a dealer added option, I pulled it out & sold it for a few bucks. I can see having one of these poorly designed things in your car to keep it factory original but that would be the only reason to have one imho. Jerry

[67Twistytee]

Thanks Jeff

I climbed back in with a spare battery and no dice. Maybe the magnets are shot after almost 50 years. I've attached a few photos and opened it up in case anyone is interested in how these were made. Lots of true copper wire and two rare earth magnets that spin around the shaft as it gets power. Maybe a motor shop could solder in new magnets, but it's probably cheaper to find a working unit.

[67Twistytee]

Some shots of the motor

[ERIC AULL]

Check the ground to body...could be just not a good ground after all these years!

[67Twistytee]

I was able to get it working again. The winding was binding against the rotor. I was able to pull it apart, move the winding and then reset it. I cleaned and relubed it with Wurth HHS and put everything back together. Hardest part was getting the spring loaded magnets back in their slots. I know it's a bit of a novelty accessory as there's no heating element to assist in defogging, but it's neat to get the original fan going again. The two speed resistor on the switch still works too.

[GT182]

Andy, I had the rear defogger in my 1st 66 GTO back in 1970. As you say it worked but cold air only. A friend of mine with a 66 GTO up North made a duct to pull air from under the rear seat for it. Then it worked great for the winter months or when the rear window fogged up.

[1967SC]

Mine is non functional too,I will be trying to test mine with a battery.
Thanks for posting this,it just what I needed to address the problem.

[Jeff Hamlin]

What always amazed me was the placement.
I know the rear speaker played into this but why the he!! place the vent/fan directly behind the drivers side and
not center where at the least the football size area that it does clear would at least be in the mirror sight line

[694.1]

The only hard part is re assembling and getting the magnets back in!

[67Twistytee]

I first attempted to hold the magnets with painters tape but it wasn't strong enough. I resorted to using two screwdrivers from an eyeglass repair kit. Took a few tries but I was able to hold them against the springs long enough to insert the spindle shaft. I also used some WD40 on a Qtip to clean the residue on the copper contacts surrounding the spindle barrel.

Agreed with the design and placement Jeff. It's placed directly in the drivers blind spot. Most of these probably got removed when people put in a dual speaker stereo system.

[My442]

This place rebuilds them:

http://www.caseysautoelectric.com/

[johnta1]

Are you calling the brushes 'magnets'?
(brushes are carbon)

Usually the brushes are what go bad, or the bearings.
(or the commutator, the part the brushes ride against)

Throwing me for a loop with the replaceable magnets thing.

[george kujanski]

Those are carbon brushes, not magnets, as John says. There is not much that goes wrong with time on those, either the brushes are shot, (along with the commutator,( those pieces of copper bar on the armature), or the bearings.

George