Help! How do I know if this 15-91 potted motor is fried?
 

Hi gals and guys!
I was given a 1936 Singer 15-91 potted motor a few weeks ago. I read a few(everything I could find, really) blogs and thought I could tackle bringing it back to working condition. All the wires were bare and/or broken, so I couldn't test the machine/motor before I started taking it apart to clean. I rewired the lamp without problems; thought I fixed the connecting wires from the motor correctly. The connecting wires didn't look original to me and were exposed. I cleaned all the old grease and put the motor back together, but when I connect to the plug it doesn't work :( I need help to figure out what is going (not) on with the motor. I'd appreciate any suggestions.
PS: I'm re-posting this, because I had posted in thread already started; I didn't know how to start a new thread.
Miriam in VT

Hi,

I'd check the two motor brushes to make sure there making proper contact and put in right. Also make sure wiring order is correct and tight at bakelite junction. Make sure machine is unplugged.

Jon

You know it's fried when it's nice and firm in the middle and crispy around the edges. :)





What Jon said about the brushes is oh so true. If the brushes stick and don't make contact or if they are dirty and grimy the motor wont run, or will have intermittent stoppages.

The best place to go to to find info about the potted motor rewire is here:
{ http://vssmb.blogspot.com/search/label/rewiring }
Rain is also a member here on QB.

And, here is a thread I did when I rewired my 15-91:
{ http://www.quiltingboard.com/vintage...r-t205360.html }

Several things I noticed:
One - You'll need new wiring blocks, the ones in your pics are trashed. Sew-Classic has the machine side separately and the cord side in a cord assembly.

Two - The splices in the motor need to be done differently and soldered. The way they are in your pics they will take up way too much space and will be very hard to insulate.

Three - Looks like you have / had some cleaning to do. You got enough lint and fuzz in there to stuff a cat with.

Joe

Thank you for your suggestion Jon. I will try cleaning the brushes housing and inserting new brushes too. I know the wiring on the bakelite junction is correct (also tried all combinations with the light fixture which comes on).
Miriam
PS: Sorry for double posting :(