Set up to weld some .25 aluminum but I only get a quiet DC arc. Sounds exactly like welding steel and no cleaning action at all. I've checked and recheck settings, flipped the ac/dc switch back and forth, moved the ac balance around but no change. It's putting out the amps and melts the aluminum with ease. When I flip the switch from AC to DC the display drops a few amps. When I put it back to AC the display reads the number I set for AC again so all that seems normal.
Settings, Pulse off, 180 amp, switch to AC, freq and balance at 2 and 10, HF, Tig, 2T with the pedal, pre flow 1, post flow 6, torch in negative, clean new 6061 aluminum .25"

It's gotta be something simple.