Dan Mig 200 Amp weird issue.

[eddie49]

Yes, I think you are close to solving this!
However, we need to clarify the way that DB-9 connector pins are numbered. The numbers may be moulded into the plastic, but are very small. For the female DB-9 plug on the wiring harness, the right-hand picture will apply:

Please note that the pin opposite 1 is 6, not 9.

The red wire with the ring terminal is the positive DC feed from a bolted connection at the MIG welding torch to the board at Pins 2 and 6, but it actually may connect at the positive terminal of the motor.
The negative of this DC welding output, from the choke, is a blue wire to Pin 7 of the DB-9.

 

[ng8264723]

Hi Eddie
I think I got it. I went over all the terminal numbers from above and made a diagram. If you can give it one more look and agree I will attempt to wire it up friday! I am excited i think we got it


BTW if you are correct this welder was wired awfully by the previous owner. It's really tough to fix when you have no idea of the original configuration.

 

[ng8264723]

Pic

 

[eddie49]

Yes, your drawing in Post #43 looks correct to me.
Maybe in view of the changes and uncertainty, it might be wise to temporarily put a fuse in the 24v AC circuit? Connect either of the two secondary output terminals to it's wire via a 2 Amp fuse. The transformer runs the operating coils of the contactor and the gas valve, I think 2A should be enough for that.

Before that, when you wire up the primary of that transformer, it would be a good idea to make sure that the 110v and 220v supply wires go to the correct inputs. As I suggested in Post #22:

"Before connecting the primary of the new transformer, set the jumpers for 110, power up the welder, and confirm which wires show 110 volts across them. The set it for 220, plug in to your 220 supply, and check the wires again."

This transformer gets mains power as soon as the welder is plugged in, so there is no need to press the trigger switch. On the $44.74 transformer that you linked to, the common is White, the 110v input should go to Black, and your high-ish 245 volt supply goes to the Orange wire.

 

[ng8264723]

Thanks! It took me a while but I got there. The I will surely add the fuse! I was wondering why the input wires were marked (O and F). I bet the directions gave the correct location for the common wire. I will chase it though by plugging it in as you suggested.

Wish me luck!

 

[ng8264723]

Well i got the coil installed. I figured out the 110 and 220 volt wiring and the secondary wiring. Unfortunately, I think the PCB has some issues. I wonder if that is why it was rewired. I was able to test the contactor with the coil by jumping out the pcb leg. It worked well and the d/c from the recifier has 20 volts and more when I turned the heat. The torch switch was checked and worked well. No more blown fuses. The issue is the PCB is not working correctly. I will send to Les for a repair. I bet the PO jury rigged it to work but not corrcetly