Miller Dialarc HF Gas Solenoid Issue.....

Hey everyone, maybe someone here has some experience with this issue, or machine repair, and can point me in the right direction....So I just picked up a 70's or early 80's Miller Dialarc HF from a local auction....the thing works great so far, High Freq works in both continuous and start modes, foot pedal works, so that's about all I really need from such a basic machine....

well the gas solenoid is acting up....and actually it looks like a newer solenoid...When I got the machine the solenoid was disconnected from its wires, and was just hanging from the gas hoses....So I put it back where it was, and hooked up the solenoid.....granted, I prob should have metered the wires first, but it prob wouldn't have mattered cause I wouldn't know the proper polarity for the solenoid anyway....But regardless, I hooked it up with 50% probability of getting it right....

so when I use the pedal, the HF and the current control both work like they should, but the solenoid doesn't actuate with the foot pedal.... When the machine is in remote contactor mode, the solenoid is just open all the time.....if I flip it to Standard, the solenoid closes. Flip the switch back to Remote, the solenoid opens until I flip it back to standard, or turn the machine off. Currently my workaround is just to use a torch head with a valve on it, and just flip the gas on and off as needed....also, the post flow is set to minimum currently, I haven't even messed with that so yet.....

Also, I just swapped the leads on the solenoid, and it does the exact same thing.

So the solenoid WORKS, but it just isn't being actuated with the pedal when the contactor is in remote mode.

Hopefully someone here can point me in the right direction. Thanks!

Nate.

If you go to the Miller website you can download the manual for your welder. It should include an electrical schematic that will show how the solenoid should be wired up. I'd be suspicious of the post flow timer.

Yeah you don't have a fault with the solinoid, you have a fault in the electrics driving that solenoid. Solenoids are just coils, does not matter one iota what way around the 2 wires go.

Agree, I have the same machine and had to replace the post flow timer.

ewlsey said:

If you go to the Miller website you can download the manual for your welder. It should include an electrical schematic that will show how the solenoid should be wired up. I'd be suspicious of the post flow timer.

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I had a very similar issue due to problems with the foot pedal switches. I'd check that you are getting both signals.