I have a Kenmore 159.18131 that is bound up. The hand wheel will not turn. I am looking for a service manual. Does anyone know where I can find one?

CENTER OF HAND WHEEL

Sounds like your machine needs professional service.

Looks like the machine is bound up, or the motor is failing. If the hand wheel is easy to turn then it is probably the motor drawing too much current.
Brother recommends a new motor and belt every 1500 hours of run time.

My sewing expert (spouse) says you may have thread caught in the bobbin area. Remove all the thread from the top, they look inside, you may find the problem.
Be blessed.

turn the hand wheel, perhaps?

as for the hand wheel not not being able to turn, it's possible that something could be loose or broken

you said it's been sitting for several years,, I would suggest that the machine needs to be serviced
by a sewing machine repair shop, where they can check the handwheel & find out why it won't unlock, & that the gears & inside the machine can be checked & grease & oiled & the timing check also

Sound like you need to take it out of bobbin winder mode. Suggest looking for a way to engage the clutch. Turn the center knob on hand wheel and or move the bobbin winding post back to postion.

The center hand wheel should move about 1/3 turn towards you to look it back into place.

it sounds like the belt to turn the wheel broke

you shoul check your manual.

If you don't have one,
I'am not sure what this machine looks like,

On the top part of the machine, put your thread on the thread spool,(on the right) the thread should be brought over to the left side and wraped around a small button looking piece. then brought back towards the spool of thread, bring the thread through a small hole in the bobbin, pul 2-3inch out, place the bobbin on the small metal bobbin holder and push to the right,

make sure pressure foot is up. you will need to loosen the hand wheel, hold the hand wheel with the left and and with the right hand turn the center circle back to it loosend (counter clockwise)

make sure the bobbin wind evenly

If your gaskets are bad, the machine will not rotate. Can you move it by hand? If not then have you checked the gasket in the back of machine that comes in contact with the hand wheel? If it is making contact, this is what runs the machine and both the little black gasket and the hand wheel will spin when you rotate by hand. If the hand wheel is free spinning then it may need oiled. If you have a manual, try oiling the complete machine according to manual.