As far as recs gating on you either need a handyman or you can make a tester with a flashlight and some wire and alligator clips
As far as pot wire if you get no change check
The wiring to and from pot I will look and see if I have info on making a tester you should get 3-4 volts and then drop as you press accelerator if you type in how to make an scr
tester with flashlight it will show how also show how to use as far as the shunt it should read ohms