I have an Airco Heliwelder IV, 300 AMP; serial #MG912011 that is exhibiting continuous post flow regardless of the post flow or other settings. After review of the troubleshooting guide in the owner’s manual, I replaced the post flow potentiometer (w/ Honeywell Clarostat RV4NAYSD105A) which did not cure the issue. It appears the potentiometer may have been changed previously and I’m suspect of the timer as well ((#CLF-41-30060) 24v). Can anyone provide insight into curing this problem? I can provide further details related to the current installed components as well as photos.