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MG TD TF 1500 - Arnolt Heater Motor Wires

I'm restoring two Arnolt heaters. The insulation on the motor wires is stiff and very brittle. I can slip heat-shrink tubing over them at the opening in the motor case, but any movement will break the insulation inside the motor case that is below the heat-shrink.

> Any suggestions on how to make the wires safe?

> How can I secure the wires so that they can't move and break?

> Have any of you replaced the motor with a modern motor? Make, model?

Thanks,

Lonnie
TF7211

Photo -
Left: Motor from Arnolt with cast front and thick heat exchanger
Right: Motor from Arnolt with stamped front and thin exchanger


LM Cook

Have you double checked that they work?

I have one Arnolt installed and a couple on the shelf, but it has been about a decade since examining an Arnolt motor.

First off, if you remove the two screws and separate the cases, you see where the wires attach to the brush holders. You can attach new wires there and start from scratch. Maybe I'll see if I can peek into one tomorrow.

With that said, I recall electing to replace the working unit's motor with a slightly larger, newer one. There's not much extra room and for the life of me, can't recall where the replacement came from. Being a horder has its advantages. I swore after installing the Arnolt, I'd never ever remove it.



JIM N

Lonnie,
I agree with Jim, replace the wires with modern FLRY automotive cable and check the brushes while you are at it. They might be worn close to the limit.
Regards
Declan
Declan Burns

Thanks Jim and Declan,

I separated the case on one of the motors a couple of years ago. Couldn't see how to easily replace the wires. Spent another four hours getting the brushes back in the holder to reassemble the case. There is only a 3/8" space to work and the brushes are not directly in front of the opening.

Any advice on how to replace the wires and to reassemble (faster than four hours)?

I'm restoring one of the heaters to donate to the auction at GOF-South in April, so I don't want the winner's car to burn up. I'm putting the other heater in my TF ... don't want it to burn up either!

https://www.gofsouth.org/

Lonnie
TF7211


LM Cook

There was a guy named Ben Cordsen in Colorado that restored these heaters. I think he is a artist? If he is still around he could likely advise or help you. George
George Butz III

Thanks George,

I bought an Arnolt label from Ben a few years ago. I'll keep him in mind if I can't find some local help.

Lonnie
TF7211
LM Cook

I dragged a complete Arnolt heater home and tore it down while watching Jeopardy. This motor may not be an original but it is a typical fractional hp series motor.
I know the hot wire has been replaced with a more contemporary red wire with fuse holder. Maybe it was corrosion or manhandling but the soldered pad between incoming red wire and the upper brush lead has detached. I'll keep the red wire and epoxy that pad back down to the insulator.
You can see how the lower brush wire joins the black fabric insulated wire that runs into the field windings. The black wire running into the motor is visible in the tin case, upper right hand, and is crimped to the other end of the lacquered field wire. There's a paper insulation, a tube about an inch long, that nestles in next to the field winding but I dug it out to show the continuity from the black fibric wire to the field. I'll nip that deteriorated black wire off and solder on an new wire out to a clean ground lug.
Notice, the brushes are not visible as they are shoved back into the brush holders and held there with a toothpick snapped in half and slipped into the sides. The armature commutator slips in and then the "lumber" is removed... after a few drops of oil drizzled into the bushing.


JIM N

Thanks Jim,

Your pictures and comments are a big help. Now I gotta decide if I have the nerve to completely separate the case and update the wires.

Lonnie
TF7211
LM Cook

This thread was discussed between 15/02/2022 and 18/02/2022

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