thunderbolt 225

[shinnyboots65]

good evening this is my first post to your web site I have a thunderbolt 225 ac/dc welder and I am having a problem with is I took to a place here in Memphis to get it repaired and all they did was rewire the main power cord and tell me the plug was bad on the end and charged me out the butt for what they did that being said I brought the welder home and placed it in my shop for a couple of months because I don't use it every day or every weekend ( part timer) well I replaced the plug on the end plugged the welder in turned it on the fan came on so I tried to weld with and it fizzled a little and the there was no spark at all I cant even get a spark by touching the ground and lead together I have checked my power source and am getting voltage to the switch but that's all I know how to check I've seen on line about diodes going bad but I do not know how to check them anybody got any ideas hate to take it back to same place for fear of being taken advantage of again any help would be appreciated thanks

[Aeronca41]

Welcome, shinnyboots65! Sorry to hear about you getting taken on the (non) repair. Will try to help.

Does it fail on both AC & DC? The diodes are not in the circuit on AC. If it fails on DC only, the diodes are suspect.

Do you have a multimeter? What is your level of electrical experience? Welder powered off and unplugged, Diodes can be tested using the Ohms function--you should have infinite resistance (OL for Overload on most meters, or a very high resistance) with the meter leads connected to the diode one direction, and a very low resistance if you reverse the leads. If you get the same reading with the leads both ways, the diode is bad-doesn't matter if resistance is high ( diode is open) or low (diode is shorted) - if it's the same both ways, it's toast. Disconnect one lead of the diode from the circuit while testing.

If if the problem is on AC also, the problem is likely something else.

Do you have the manual/parts list? You can get one by entering your serial number in the link under RESOURCES at the top of this page. Please post your ser number so we can look at the manual.

[davido30093]

What type of plug did you put on it? What type of outlet are you plugging it in to?

[ryanjones2150]

thunderbolt 225

My first ever welding machine that was mine...all mine...was an old thunderbolt that a friend of mine gave me when I got out of the army. Took it home, put a new plug on it...red and black to hot, green to ground...dang thing hardly worked. Took the cover off and found the green and red INSIDE the machine were swapped. Flopped the wires and it worked like a champ and is still going. Take the cover off and take a look.

[shinnyboots65]

Welcome, shinnyboots65! Sorry to hear about you getting taken on the (non) repair. Will try to help. Does it fail on both AC & DC? The diodes are not in the circuit on AC. If it fails on DC only, the diodes are suspect. Do you have a multimeter? What is your level of electrical experience? Welder powered off and unplugged, Diodes can be tested using the Ohms function--you should have infinite resistance (OL for Overload on most meters, or a very high resistance) with the meter leads connected to the diode one direction, and a very low resistance if you reverse the leads. If you get the same reading with the leads both ways, the diode is bad-doesn't matter if resistance is high ( diode is open) or low (diode is shorted) - if it's the same both ways, it's toast. Disconnect one lead of the diode from the circuit while testing. If if the problem is on AC also, the problem is likely something else.Do you have the manual/parts list? You can get one by entering your serial number in the link under RESOURCES at the top of this page. Please post your ser number so we can look at the manual.

I called myself checking on both ac/and dc and nothing on either side of course i'm not real experienced with d/c welders I've always had a old Lincoln 225 cracker box that's welded a million miles of rods but I will check these out to make sure can you recommend anyone in the Memphis area that can repair this with ripping me off

[Aeronca41]

Sorry I don't know anyone in the Memphis area; maybe someone else will see this who does. Do you have any friends with electrical experience ? These welders are not very complicated and perhaps someone with some electrical knowledge and the schematic downloaded could figure it out. Is this the earlier thunderbolt with the separate AC and DC plugs on the front and the crank on top or the later one with the crank on the front and a selector switch for AC/DC? The guy who took your money did put on a 230 volt plug, didn't he?

[ryanjones2150]

thunderbolt 225

I agree, they really don't get much simpler than the thunderbolt. Snap a picture of it and post it so we know which machine you have. There are several versions of it has the years have gone by. Mine, for example, is AC only and separate plug-ins on the front for high and low range output and a crank on the top to adjust the amperage. Take that sucker apart and look inside, you can't possibly do a worse job than the guys who stole your money.

[Aeronca41]

I agree, they really don't get much simpler than the thunderbolt. Snap a picture of it and post it so we know which machine you have. There are several versions of it has the years have gone by. Mine, for example, is AC only and separate plug-ins on the front for high and low range output and a crank on the top to adjust the amperage. Take that sucker apart and look inside, you can't possibly do a worse job than the guys who stole your money.

...and please post the serial number so we can tell which manual to look at.

[shinnyboots65]

thunderbolt 225

the serial number is le030093 stock number is 90362 the plug is a 230 volt plug and the amps check out to the switch as 230 volts so I assume this is right I will try and download the wiring diagram and do so tracing and I also want to say thanks people for the help

[Aeronca41]

Good info. I have one like it in the shop. Let me take the cover off tomorrow and see if I can give you some things to check. Do you have any experience working on live electrical eqpt? Using wiring diagrams? What sort of meter do you have? Don't want to get you hurt or killed! Maybe it will be as simple as a corroded or loose connection, but will probably require some internal voltage checks.

[Aeronca41]

Looked at the manual-Going to need a photo of or all the info from the model/ serial number plate. There are multiple versions covered by this manual with diff connections inside. Could not find any info online from the stock number.

[ryanjones2150]

thunderbolt 225

My machine is a lot older than that one, which is probably why it still works. Even so, can't be a whole lot of things to check in there. I could be wrong though. Yours might have a miniature nuclear reactor inside.

[Aeronca41]

My machine is a lot older than that one, which is probably why it still works. Even so, can't be a whole lot of things to check in there. I could be wrong though. Yours might have a miniature nuclear reactor inside.

Lol, All of the machines addressed by the manual related to that ser no are very simple. One has 115/230 jumpering capability inside and there are overall about 5 or 6 variations of the wiring diagram. But, all are transformer with movable coupling for current adjust, power and polarity switches, a (thankfully!) non-nuclear reactor 👍, and some diodes and caps. I sure hope we can help shinnyboots65 fix this long distance without getting ripped off again. Hope it's nothing serious.

[ryanjones2150]

thunderbolt 225

Ya, you're probably right. Nothing near the nuclear fusion or atom smashing level of difficulty. The only machine like that that I've ever seen fail (I'm sure there are others, so don't anyone go beating me up), did so because of mechanic damage. Seems like it got backed over by a forklift or something. So, unless he's a really bad forklift driver, I think we can help him at least determine if it's a salvageable piece of equipment.

[Aeronca41]

Really need the info from the data plate. The manual shows a 460-volt version that is not adaptable to 230 v. Hope that's not the problem-not many of us have 460 in the garage!