Singer sewing machine model number 237 ?

My sewing machine has started to go on its its when swiched on and the pedal starts smelling of burning , i looked at some of people's questions and they had the same problem, i they was told what was wrong and how to fix it and they was told what part they needed to get whichwas a singer foot control/motor capacitor soi ordered one but cant seem to see where it does go in my foot pedal please could you help.

Margaret.
June 2016