Emerson Removeable Metal Head Wire Grommet Cap Attached To Motor 1927

[Russ Huber]

That metal 2 screw plate with motor head wire grommet cap was implemented 1927 fan motor season for oscillators. 

[Russ Huber]

Emerson Screw In Motor Plate Grommet Adapter - Antique Fan Supply Co (antiquefanparts.com)

[Dave Hoatson]

There is quite a bit of wire tucked inside, but it is usually petrified from age. 

I cut the headwire open with a new #11 Exacto (I buy them in boxes of 100) to remove the outer cloth sheath and the strain relief cord knot. Once the 3 wires are separated from each other, it is much easier to pull them out one at a time. Use a heat gun to soften them. 
 

I cut off the old headwire, strip the motor leads, make sure the wires are shiny by scraping them, sanding them, or hitting them with a Dremel abrasive puff. 
 

I use OTR headwire, but I think Tony Clayton’s is more authentic. The OTR is smaller than the Emerson wire. I prevent the outer cloth sheath from fraying by tying a large strain relief knot, just like the way Emerson did it.  Solder the wires, then wrap each connection with cloth electrical tape (friction tape). Tuck them back in.

Most of the time, I fully disassemble Emersons, including pulling the stator coil, so I can clean the oil passages on the shaft and inside the rotor.

There are schematic diagrams on the old AFCA site:(https://www.fancollectors.org/info/Fan Wiring Diagrams, etc.htm)  but when I connect the headwire to the switch, I often do the brute-force method of seeing which of the 6 possible wiring works best:

 

Unplug the fan. 

Label the motor wires A, B, and C. It doesn’t matter which is which. 

Label the switch terminals 1, 2, and 3.  It doesn’t matter which is which. 

Set the switch to ON.

If the blade is on, make sure it can spin freely. 

Make sure the oscillation is turned off so the fan doesn’t wiggle and pull the temporary connections off. 

Wire up the 6 possible combinations (one at a time).  For example, the 1st line below has A connected to 1, B to 2, and C to 3.

  123

  132

  213

  231

  313

  321

For each combination, briefly plug the fan in and note if it starts and if it runs in the correct direction.

Unplug it. 

If one combination works, then that’s it. 

If more than one combination works, try each one in all the speeds and pick the best one. 

Touch the motor and make sure it’s not running hot.