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I have 3 bare motors, one of which I hope to use in a TR250. Two are DR3A 5407138317 ,the other is DR3A 756460 and appears to be a later motor having two spade connectors as opposed to separate wires.

Looking at the circuit diagram I thought I could test with a battery charger 4/8A.

On the older 2 I connected +ve to green and -ve to the other wires in turn. All drew current but no noticable movement. I can't believe all 3 are faulty.

Am I doing something wrong?

Thanks

Eddie

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These take about 3A to run in, if in good shape.  But there is a 10A surge at start.  Modern electronic battery-chargers sometimes trip out because of this.

If you post the actual part numbers which are like 75XXX (and then a letter after which does not mean much that is interesting), I'll be able to tell you more about them and which is most likely to be useful.

You are looking for one with a 120 degree gear.  The number is stamped on the gears.

Also for a TR250 should have three wires, not push on terminals.

The correct part-number is 75568, but these are rare and all sorts have been pressed into use.

I've rebuilt hundreds of these and have spares and such.

 

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75568 is sought after and fetch a good price, even if not working or rough.  I can rescue these from the dead, they always go in the end.

75546 is a new number on me.  75446 is Spitfire or Herald or something.  Worth about half as much a 75568.

 

 

Edited by AlanT
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It occurred to me that you may not know how to connect this.

You must identify the GREEN wire. It will be soldered to the left-hand carbon brush. That's one battery connection.

Join the other two wires together, They are RED and BROWN.  This will probably be hard to tell.  This is the other battery connection.

If it does not run, DONT leave power on.  You will burn out the armature in about 1 minute, because it will be taking at least 10 Amps.

 

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Eddie,

If it doesn't frighten you, remove the metal plate covering the rack connection on the motors, and look inside. Check that you can rotate the armature manually with ease. If not it will need to be stripped down to sort it out. Applying electrical power prior to doing this may not be a good idea.

Good luck

TT

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Thanks everyone.

I connected as per Alan's instructions and still no joy.

I have taken the plate off one of the motors and cannot move the large gearwheel by hand so I will have to strip it down. I suspect none of the motors have moved for many years so they all may be in the same state. I will report back on progress.

Regards

Eddie

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The first thing to do is remove the main gear.  These are often seized in their bearing.  Of course this stops the armature from spinning.

If you knock it out the bearing will separate from the casing. Don't panic if you do this.

It's also fairly common for the armature to be stuck.

Sometimes it's seized in the bearing in the gear-case.  If you pull on it the self-aligning bearing will pop out of its spring.  If you do this contact me and I'll help you get it back.  Easy if you know how.  Mess about and you will break the spring.

Sometimes they get rusted to the square body.  Recoverable but often the winding will be impaired by water.

The pole-piece was bored in place.  If someone who does not know turns it round, the armature will usually jam. Same thing happens if you swap the parts from one motor into another.

I could go on!  Photo shows how I remove the C-clip to get the gear out.  Watch it does not ping away.

gearout-1.jpg

Edited by AlanT
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Hi Alan,

I have removed the gearwheel, it wasn't stuck. I took the endplate off and tried to clean the commutator. The motor is now working but I suspect it was a bad connection to the brush holder because my cleaning had no effect but subsequent movement of the brushholder did.

Thanks Eddie

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Well that's good, you've made it go.  The brush arms are not a very good design.  Prone to making poor contact on the circular seats.  Common to find corrosion around there.  All these brush parts have a thin silver-plating. Some are brass others steel.

I'd take off the brushes and arms and clean the arms with a toothbrush and some yellow cream sink cleaner.  Nice cheap, fine abrasive that won't take off the silver-plate.

The field coils I clean with WD40 and a toothbrush again.

Inside the cup that holds the carbon you get contamination that can give poor contact.  This comes out with household Silver-Dip.

Not especially important that commutator is cleaned free of carbon.  More important is material between the commutator segments that makes a short. I rake the grooves out with a scalpel blade.

Broken wires where the are trapped between the cap and body are common source of intermittents.

 

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  • 4 weeks later...

As a totally unconnected, but VERY satisfied customer, I would like to recommend Alan T as a brilliant restorer of Wiper Motors.

He has returned my TR5 2 speed motor in absolutely pristine condition. He has kept me informed about what was wrong and what was needed to rectify it at every stage of the restoration. He is very communicative throughout the process and I am very pleased with the end result.

A great asset to the TR community.

Dave McD 

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11 hours ago, Dave McDonald said:

As a totally unconnected, but VERY satisfied customer, I would like to recommend Alan T as a brilliant restorer of Wiper Motors.

He has returned my TR5 2 speed motor in absolutely pristine condition. He has kept me informed about what was wrong and what was needed to rectify it at every stage of the restoration. He is very communicative throughout the process and I am very pleased with the end result.

A great asset to the TR community.

Dave McD 

I will second that Dave, This is the latest one he has done for me.

Stuart

 

ital-8.jpg

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This is the motor from an Italia I believe.  I put a new armature in it because of "black-wire".

Well eventually I rewound the armature and it put it in a rebuild.

The rebuild just sold.  I always check what car a buyer intends to put it in. And it's for a Triumph PENNANT, from 1958.

 

 

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  • 1 month later...
  • 3 months later...

Alan or anyone that might be able to help me on this......

I read the posts from last June on 75568B tr250 two speed motors. Wondering if possible you might have a suggestion on the problem I am having with this one on my work bench also the 75568B. The one in the car is fine, but I gave my good spare to a buddy in Wyoming to put in his car and he sent me a non working 75568B for me to fix for a spare.   The wires were cut off, so I soldered new wires on, cleaned it all up and it will run on both speeds, but there are times it won't start up.  I have the top cover off, cable and lever off. When it doesn't fire, all I have to do is back off that locknut  with the plastic nub a little (guessing it is just there for armature endplay),  and bump the armature shaft just behind the worm with a screwdriver and it fires up. Any thoughts? Everything turns freely.  Don't want to junk it as it will make a good spare..... except for it has a missing ear on the top of the park post where the snap clip goes, but if I ever do need it I can rob the drive gear and park out of my current motor.    

Any help would be appreciated.   Thanks

Chris     oregon250

 

 

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Single speed I know but gives some good pointers and views of what to find inside.

I particularly like the technique to true up the commutator using an electric drill held in the vice using a fine file.  Not super accurate compared to using a lathe, but if you have a flat on one segment it will probably salvage the armature.

 

Part 1

https://mgaguru.com/mgtech/electric/et217.htm

Part 2

https://mgaguru.com/mgtech/electric/et217a.htm

Edited by BlueTR3A-5EKT
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Thank you both for your replies.    Both were helpful.     Roger, you had me double checking the armature connections and sure enough, I found 2 connections that the wires were wrapped around the nub, but the solder connection was broken. That evidently was just enough to once in a while go dead, where then that little bit of a movement that I'd make to the armature would get it to go.   Once they were soldered back in....bingo.  I also like the trick of putting the armature in a drill motor. I did that with some 220 grit and it did a fine job.  Now I have a working spare.  Thanks to you both.     Cheers

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