lowjane, You have me quite confused. What I am hearing is that you have the foot pedal plugged into a 3 prong receptacle and it works. There is a dual receptacle on the same machine??? That would be a rare beastie indeed.
I am guessing that someone may have just put a 3 wire machine into a far older case/cabinet that had the dual plug in and disconnected the dual plug. The usual swap fro a knee or a foot is just to use the 3 prong. Pics perhaps??

lowjane, I'm not familiar with that model. However, I looked it up on Google and I've never seen one of those pedals hooked up to a knee mechanism.

I have another brand of machine that has that dual receptacle. Long story, short - Try reversing those plugs. Plug the knee plug into the machine plug and vice versa. It worked on my Montgomery Ward machine that had a similar setup.

bkay

Here's another thought- Leon has a point. The only Singer machine cabinets I have that have knee pedals, have the 1 button controllers (foot pedals). The later machines had a different controller. The one button controller slips right into the knee bracket without changing anything. When you press on the knee pedal, it pushes on the button on the one button controller.

Singer knee pedals were not wired - they just hold the 1 button controllers. As far as I know, Singer did not use the dual receptacle. I've only seen that on Japanese machines.

Something here doesn't make sense. Photos please.

bkay

One button Singer Controller
[ATTACH=CONFIG]589987[/ATTACH]

The later controller, which the 247 came with
[ATTACH=CONFIG]589988[/ATTACH]

Here is a picture of a typical Singer triple plug ( well, with a motor and mount). I have not ever seen a dual added to the same machine.[ATTACH=CONFIG]590006[/ATTACH]

It sounds to me like you found a Singer machine that's been put into a cabinet set up for a Japanese machine. Japanese machines used the dual outlet cord block set ups with a foot controller or a knee lever. Singer used a 3 pin junction on the machine, and on some machines had a separate spot to plug the controller(whether foot or knee operated) on the side of the machine. You could theoretically wire the Singer to work with the Japanese set up but it would be easier to find a Singer cabinet.

Cari

I have a Singer 247. It used a 4 prong controller. Haven't seen a knee control for it. Not a bad machine.
Just like a Singer 360 but doesn't use cams. Have had several of this type and haven't had any problems
with the cams. Wouldn't pay more than $20.00. No one usually collects them but they sew pretty well
and use a 66 bobbin.

I meant to say I haven't had any problem with the gears.

Dual plug. Ohh with painted markings.[ATTACH=CONFIG]590160[/ATTACH]