Miller 320 hf issues

[ryanjones2150]

I love those old machines. Glad to see you have the appreciation for them as well.

[fcanaan]

Ryan,

Yeah. That only worked for so long. I managed to find a replacement unit on ebay that is an exact match. I guess I'll swap em out and just wear the one to death.

[ryanjones2150]

I just about to say clean the crap out of your contactor...insert sarcasm at will...<br />
<br />
Glad you got it fixed.

[fcanaan]

Sorry everyone. I got it figured out. The contactor was sticking. I pulled it out and cleaned the crap out of it and it's back to normal..

[fcanaan]

Hey everyone. I'm new here, I've been watching these forums for a while now and finally have a reason to post. I have a 1969 Miller 320abp (S/N U516236) that I've been cleaning up and working on for a little while now and continue to have a weird issue. Every so often when welding in DC straight(DCEN) at the end of the weld when I take my foot off the pedal the HF seems to come on and won't turn off. Sometimes it only for a second, sometimes it's as long as post flow, and sometimes it doesn't stop till I turn HF switch from "start" to "off". Occasionally I have even turned the machine off and she continues to hum until there is finally a "clunk" and she is finally quiet. When this happens it screws up the end of my weld and is just generally disconcerting. I have both the contactor and amp control set to remote and have a working pedal. Start control is set to out. I'm on the middle detent in the amperage range dial.This happens with both my wp9 and wp20. Any ideas are appreciated.