Snap on 187 stopped

[daddy2coull]

I have a Snap on 187 mig welder, it's almost 3 years old now, but this is only the second time that I have ever used it. I was happily welding away on the back of my land rover and it's just stopped arcing. Fans and wire feed work perfectly. I've now left it switched off all afternoon thinking it may be a thermal cut out, but still no joy.

any help would be great

 

[rtbcomp]

Easy check first - has the earth (welding return) become disconnected somewhere along the line?

Does it have a manually resetable cut-out?

 

[daddy2coull]

i have checked out the earth lead and that appears fine and the is no reset switch that i can find

 

[Rig Pig]

Does anything happen when you pull the trigger? If not check the torch switch and wiring and the contactor.

 

[the snooper]

I have a Snap on 187 mig welder, it's almost 3 years old now, but this is only the second time that I have ever used it. I was happily welding away on the back of my land rover and it's just stopped arcing. Fans and wire feed work perfectly. I've now left it switched off all afternoon thinking it may be a thermal cut out, but still no joy.

any help would be great

Does anything happen when you pull the trigger? If not check the torch switch and wiring and the contactor.

 

[Rig Pig]

That will teach me to read through instead of skimming! Straight to the contactor as first suspect then!

 

[daddy2coull]

lol, ok i'm a complete novice here, where would i find the contactor?

 

[Maker]

Could there be an internal fuse that's blown?

 

[daddy2coull]

could be, but surely a blown fuse would stop the wire feed too?

 

[mike 109444]

Do you have a pic of the welder as I think you will find the Snap On welders are rebadged Cebora welders.
So not so sure they even have a contactor!
Pics of a couple of contactors. First pic it is the white item on the right.
Note both have a "manual" button to operate/test the contactor.

 

[Rig Pig]

My old 130 is a Cebora underneath, it has a contactor.

 

[mike 109444]

Is the gas valve still operating ?

 

[daddy2coull]

just had a quick play. switches on with power lights on switch and main power switch. fans run. i have continuity through the earth lead and i'm getting gas out at the gun. but no welding even directly onto the earth clamp.

I have found the contactor with what appears to be a reset button that is in the OUT position. I can push it in, but it will not stay in.

where do I go next guys?

 

[daddy2coull]

it looks the same as this

 

[daddy2coull]

lol, i just can't leave things alone, if i push in the blue button on the top of the contactor the welder now arcs. so come on guys, where do I go from here?

 

[Maker]

Tape it in.


Only joking, don't do that. Can you replace the contactor?

 

[daddy2coull]

lol, i did think about it just so i can finish for the weekend!!! i can replace the contactor. it looks like a straightforward job. but i'm guessing it works like a relay, so there should be a signal getting to it to energize. where do i check the input feeds?

 

[Wendelspanswick]

Y

lol, i did think about it just so i can finish for the weekend!!! i can replace the contactor. it looks like a straightforward job. but i'm guessing it works like a relay, so there should be a signal getting to it to energize. where do i check the input feeds?

The contactor is a big relay, you will have the heavy gauge wires which are the switched contacts but also a pair of thinner wires which are the coil wires, possibly labelled A1 and A2, pulling the trigger should provide a voltage on the coil wires, you need a meter to check.

 

[daddy2coull]

ok, feels like i'm getting somewhere now. i have 26v between A1 and A2 when I pull the trigger. so can we safely say its just the contactor?

 

[daddy2coull]

is something as cheap as this one ok or should I visit a welding supply company?