Synchrowave 200
AC setting
3/32 green band
120 A

Having problems welding aluminum with my machine. Does fine when cold but after a few minutes it will not weld aluminum or steel at all. Has a very erratic arc on aluminum. On steel, DC setting 75A (Red band) It welds like its on full power. No control of arc when pedal is depressed.
Anyone have this problem before?