Singer 15-90 Restoration: Part 2

Here is the second installment of my continued effort to restore my Singer 15-90 sewing machine, part one can be found here.

The 15-90 is an interesting machine because the electrical system is not built in. So it’s only a matter of a couple of screws and poof you have no trace of electric power. I knew that my machine needed electrical work because the first time I plugged it in the motor was running but couldn’t turn the belt and the foot pedal wasn’t consistent. The lightbulb however worked great.

So the next task on my list for restoring this machine was to take apart the electrical system to see what is going on. First up was the light fixture:

My light fixture is not in ideal condition… it wasn’t a factory standard to tie these on. I cut the string and removed the electric tape and saw that the light fixture attaches to the machine body with two small screws:

As you can see one of the holes on the light fixture body is broken, I don’t know if I can substitute a different screw to fix it or if it will have to be replaced. I looked all over the internet but I couldn’t find anything that described how to remove the light cover to change the bulb or clean the glass (the 15-91 has a different and easier set-up) So here is my trial and error guide to:

How to Take Apart the 15-90 Light Fixture

First up since the fixture is completely covered I would undo the two small screws holding the light to the machine so it is easier to work with. Next on both sides of the cover are these thin metal pieces with ridges at the top:

These must be bent and lifted away from the cover, I stuck a screwdriver into the ridges on the end and they came up just fine. With those metal pieces lifted away the cover will come off in your hand. Then you have this:

To remove the lightbulb press it down into the base and turn it counterclockwise. To replace the lightbulb line up the notches, press it into the base and turn it clockwise. The cover can be pulled apart so you have this:

As you can see my pieces are in need of some cleaning. To put the light fixture back together, reassemble the cover by sliding the glass into the metal cover and snapping them back into the black cover. If you put the metal back first the glass will not fit. Hold the metal rods apart and put the cover onto the lightbulb and snap the metal rods back into place. The light fixture can then be screwed back onto the machine and it’s good to go.

To continue taking apart the electrical I unscrewed the motor from the machine body:

It is horribly dirty and grimy behind the motor and if you look close at the connections the insulation has crumbled away leaving exposed wires, here is a close up:

With the motor unattached the 3 pin terminal (where the power cord plugs in) on the side has to be unscrewed and you can lift away the entire electrical system. Here it is laid out:

I took apart the 3 pin terminal to see how my components were connected, besides all the exposed wires, I saw both the foot pedal and motor wires were barely connected/falling off the terminal. As you can see in the picture on the right insulation was just crumbling off the wires.

So I will need at least a new power cord, insulation for the exposed wires, and then I can plug it in again and see where I am at. I am hoping the poor connections indicate that once reconnected it will work fine… fingers crossed. For now I am going to work on cleaning and oiling the machine. I should be able to get it sewing by manually turning the wheel until I can order all the parts I need to make it electric-powered again.

UPDATE: How to Clean & Restore Vintage Singer Sewing Machines the eBook is now available in the Zounds Shop! Save and print all of the information you need to fix your machine! 

More to Read!


  1. Have you been here, yet? She has some great repair tutorials as well as machine reviews and sells parts. She has the new wiring for your machine. I was blessed to find a 1951 15-91 and a 1938 201-2 (I think your grandma’s machine is the treadle version of that) for $10 each at a garage and estate sale, the 201 is in a cabinet like your 15-90 and the 15-91 is in a portable case. Both are in pretty good working condition, but will need some love to get them in peak form, so I am following your blog with interest. Have you been here: And I was wondering if you were considering reverting your 201 back to a treadle?

    • I have been to both of those sites! I went crazy with researching this machine, I think I read everything the internet has to offer. My grandma’s machine is a little kooky because it’s a treadle table but a newer (1938) machine installed in it and I can’t tell whether it was electric to start with or not. So no, I think it would take too much tinkering to make it work with the treadle table it’s in. Although a treadle machine would be an amazing addition to my project room. Good luck on your 15-91 and 201-2! Check out my newest post which is all about deep cleaning vintage Singers.


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