Trailblazer welding erratically

[Toadcan]

I had the tech change the brushes. Nothing changed. Is that the same thing as the slip rings? I really wish he’d have tested it after he changed them. I’m sure he’d have noticed something wrong still.

[Bushytails]

I usually start by cleaning the slip rings for any erratic issues on an engine welder.

[Toadcan]

My Trailblazer 302 is welding very erratically. It will weld fine then suddenly pulse to a higher amperage which blows the puddle apart. Very frustrating. Any ideas?