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GT6 Wiper Motor problem and time capsule

Richter12x2

Jedi Hopeful
Offline
Good morning!

It's been a long time, and still struggling through trying to make this thing go. Now the wiper motor has gone out again, the armature is a crispy and the transformer is fried shorted, so it resisted a rebuild (until or unless someone can tell me what size magnet wire that is, when it gets so small it's impossible to measure accurately with a micrometer). This was likely due to the wiper motors being wired backwards, and voltage being wired to the switch instead of ground.

I had just about resigned myself to retrofitting a later model motor, or even one of the little hotrod direct mount wiper motor posts, but then I found someone selling a New Old Stock wiper motor for a Jaguar on eBay that looked suspiciously correct.

Just received it, and it's still in the plastic, from 1966. What I thought was a silica packet was actually a small pack of parts (the nuts and replacement rubber mounts) and a set of instructions from half a century ago. So I thought I'd share:

Unfortunately, even wired as instructed, it doesn't want to do anything. I've ohmed the armature windings, and opposite sides are at roughly one ohm. The brushes are correct, the wires have continuity to the post. I can turn the armature by hand and it turns the whole assembly. However it's full of thick black grease, and figure it's probably too thick for the motor to move, so I'll be cleaning it out today, and fingers crossed, have a new wiper motor, so we can pass inspection once the world opens up and is reasonably safe again (and the car drives more than a block without dying).
 

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I tried looking at the pinout (second picture you attached). I cannot read it. Can you post a larger or clearer picture of it?

Dan Masters put together a couple of documents and drawings of the DR3A wiper motors. They may be quite helpful in sorting out what wires go where and how the switch is supposed to work.

The link below is to one of Dan Master's wiper motor articles.
https://vintagetriumphregister.org/wiper-problem/

As a footnote, since the donor of the motor was a Jag, you may have to remove its cover, extract the Jag drive gear, and replace it with your old GT6 gear.
 
I tried looking at the pinout (second picture you attached). I cannot read it. Can you post a larger or clearer picture of it?

Sure - the picture I have was really big, so I tried to scale it down for the forum to be under 100k. I'll try attaching the original, which is really clean.

As a footnote, since the donor of the motor was a Jag, you may have to remove its cover, extract the Jag drive gear, and replace it with your old GT6 gear.

I'll have to take a look at that and compare the two, if I can get this one to run again. I got it apart and cleaned up this morning. So I'm going to slowly reassemble, lubricate it and test and hopefully it'll work again.
 

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I found a document that should be much more helpful than what I posted initially. See the PDF linked below.
https://www.thorden.dk/Teknik/two-speed.pdf
This was written for Lotus owners converting from a single to two speed wiper motor but is very applicable to what is on our cars.

I have not read all the document yet. However, a lot of the information starting on page 6 should help get the motor to run the bench and then of course... in the car.

EDIT: I also found the very interesting video linked below. The narrator shows bench testing the GT6 version of the DR3A wiper motor. The dash switch is more complicated than I remembered.
https://www.flickr.com/photos/90670218@N04/26091277203/

Also, I'm sorry but the second copy of the Jag schematic you posted is even harder to read than the first copy you posted. Perhaps you can find a way to photograph or scan just the top two portions of the page since they deal with using the motor in a 2-speed application.
 
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