Gas solenoid wont open! Help

[kiquee]

I have a Dayton 160 amp mig welder model #3Z914E. My problem is I turn on the machine, turn on the gas and then hit the trigger and no gas comes out of the solenoid to my gun. I turn off the gas and bleed it and then hit the trigger and the solenoid opens and closes with no problems, but not when there is pressure against it. I've also hit the trigger to open the solenoid and then open the gas and it flows good through the gun. When I let go of the trigger the solenoid shuts off the gas and then I hit the trigger again and it wont open. I measured the voltage to the solenoid and getting a -12.7 dc volts when I hit the trigger, the solenoid is a 24V-DC 6 watt. What do I check for? Need to get this going to finish my project.

 

[piman]

Hello Kiquee,

try a voltage measurement with the solenoid disconnected and see if you get 24volts? I'm wondering if the solenoid coil is on the way out and is dragging down the applied voltage. If the voltage is still low when disconnected then the power supply is faulty.

Alec

 

[Robotstar5]

Could also be a sticky solenoid, try a couple of sharp taps on the brass part to free it.

 

[kiquee]

I know it's not the solenoid, cause I bought a new one thinking it was the problem. It's doing the same thing with the new solenoid. I'll try the voltage measurement with the solenoid disconnected after work today. What else could it be?

 

[smithyboi32]

sounds a tricky one ... you only have the gas gauge and solenoid that controls the flow of gas , as its not you gauge and you have a new solenoid , maybe the control bored ? loose wire ?

 

[kiquee]

Yes tricky it is. No loose wires, machine was working great a couple weeks before and now it's not. I'm thinking when the pressure from tank is applied that there is not enough voltage being applied to the solenoid to open it, but with no pressure it opens with no problem. So, leaning towards the control board, maybe something on the board is wearing out. But what do I check, what diode or capacitor reduces the voltage to 24v to the solenoid? Not too savvy with that kind of stuff, is why I'm asking you guys. Don't want to take it in for repair and pay more than I need too.

 

[BrokenBiker]

it wont just be one capacitor or diode, there will be diodes and resistors in series and parallel, possibly a bridge rectifier and a smoothing capacitor if ther is ac in and dc out for the solenoid.

 

[mike 109444]

Kiquee If you trace the wires from the valve back to the board it may be feed from a relay (as the coil in the valve will draw a fair bit of current compaired to other parts) Could be that the relay contacts are dirty or duff and not passing enough current under load but as said earler metering with valve disconected may show the 24v that the valve needs.

 

[mike 109444]

PS most of these valves use the incoming gas flow/pressure to help close the valve when not energised. That's why they have an IN and OUT usually denoted by "IN" or an arrow.

 

[kiquee]

Thanks Mike, I noticed the control board in the machine and didn't have enough room to look around. Will start to take it apart and do as you said, even take some pictures of the board and measure the current when disconnected. Will look for relay too. I'll get back with you guys with what I find. For now I'll be using my TIG machine to finish up. Appreciate the help guys and hope to get this machine going soon.

 

[smithyboi32]

follow the wires from the solenoid back to welder , attach the volt meter to the board or the ends of the wires and pull the trigger. if you got voltage there then you know it the solenoid , if not then you know its the board.

 

[kiquee]

Thanks everyone for your comments and suggestions. Got my machine up and running. Had let my neighbor borrow my Mig and has to change out the plug for his outlet and when he put it back together to give to me he had crossed two wires and I was only getting 110v to the machine instead of 220v. Whew, should of checked that first. Again thanks for all your help.

 

[Robotstar5]

Thanks for letting us know