hi, I got a '72 sa200 f163 machine, it runs fine but it won't weld. when my grandpa had it we had to flip the high idle switch on manually then it would weld. now flipping the switch doesn't do anything. i tied all the wires from the switch together to see if it was the switch but nothing changed. wondering what i should check next , the soleniod or something in the generator part. GREATLY APPRECIATE ANY HELP!