Miller 185 with pro star gun Trouble need help

[1v6pony]

I just bought this Miller 185 used, First couple passes worked great,
Tried to use it this morning . The Wire with out the trigger being pulled melted as soon as I touch the steel, melts all the way to the end of the tip.
any ideas on this , is the gun bad, Can I open I up and repair it. Is something in the machine bad..
I need to know, it might get returned or have the guy give me one of his other guns.
Thanks

[Danny]

Sounds like the contactor may be stuck in the closed position.

[1v6pony]

Thank you for the help , but I do not know what a contractor is other than the guy that works on my house.
I have thought it might be a relay?

Sounds like the contactor may be stuck in the closed position.

[1v6pony]

Retract this info below, thought I was looking at relay schematic on cover or machine, it is not..


Ok I am looking at the relay schematic and it appears that the 37 wire and the 38wire are reversed at the relay.
Also the number 1 terminal on the relay side is missing. It looks like someone took that wire and directly attached it to a yellow wire coming from below.
does any of this make since why someone would do this or was it a mistake?
in other wards should I just switch the wires on the relay and try it, I do not want to fry anything.
Thanks

[1v6pony]

so after a conversation with miller, It looks like they agree, it is the contactor.
I did remove the small cover on it and cleaned up the tabs, but is still did not work, So I ordered one, we will see if that fixes it.

[Metjunkie]

Pony,
I have a MM185 that I purchased new in the late nineties. If you like, I'll pop the cover tomorrow and have a look at the wiring and see if what you wrote in post #4 is correct.

[1v6pony]

Thank you that would be great
Also I spoke with the guy I bought it from he said it the inside has not been touched in the 8 years he has had it.

[Metjunkie]

Pony,
Took a look inside my machine today and took a picture of the relay and contactor. When you say you pulled the cover off and cleaned the terminals, I'm assuming you mean the relay? The relay is the small "cube" in the upper left and the contactor is the large copper terminaled item to the right. With the machine off and unplugged, you should be able to depress the spring loaded center section of the contactor. If not, then Danny would be correct and the contactor is stuck. With the machine plugged in and on, you should see the relay and the contactor pull in(energize) when you pull the trigger. The fact that it worked when you first got it tells me the wiring placement is not the issue. The schematics in the owners manuals leave a lot to be desired. If you're still having problems after replacing the contactor, post your serial number and hopefully Cruizer can lead you to the problem. Hope this bit of info is helpful. Good luck!

[1v6pony]

No it was the contactor that I pulled the cover off of, It has 2 small screws and them it comes off and you can see the clips. I cleaned them but no go.
I will look at the relay and contactor when the trigger is pulled and when it is first turned on and see if the react differently.
Thanks for the help

[1v6pony]

guess what , I pushed in the contactor tab it did not move more that a 16th of an inch, I looked at the relay and say it working at least I way one contact move.

As I was looking at the contactor, I kept pulling the trigger on and off and all of the sudden the contactor tab moved in like 1/4 of and inch and then released.
So I checked the wire and no sparky...
So it looks like it was the contactor and the cleaning helped but the tabs did not seat well.
Bummer I just got confirmation that my new contactor is on the way.

Thanks again for all the help.
Brad

[Metjunkie]

Brad,
Glad you got it figured out. I don't know how much that contactor set you back, but you may be ahead of the game if you go ahead and install it when you get it. That contactor in there now could be on its last leg. It wouldn't surprise me if it sticks on you again at some point. There's nothing more frustrating when you're in the middle of a project and you have to keep fighting the welding machine. My 185 has been one of the best machines I've ever used. The only way I'd get rid of it is if somebody pries it out of my cold, dead hand.

[1v6pony]

Well I guess I spoke to soon, I received the contactor, It is a lager unit than the org.
Turned on the machine and is sounds like gears grinding, I opened it up and did the same thing the relay is lit up like a Christmas tree as soon as it is turned on with the gun plugged in and without it plugged in.
any ideas?

Did the new contactor need to wired differently
Thanks