Serial JG004966 A few years ago a client gave me a small welding trailer with this miller on it. I have a welder on my service truck, a couple in my shop at home and another in my work yard so I didn't really have any use for it so I gave it to a welder friend of mine. He fixed it up and added a couple of tool boxes and figured to use it as a backup for the one on his truck or have for his son/apprentice to use. I think he had some trouble figuring out the throttle solenoid so he wired it with a switch direct to battery. Not sure he did that correctly, because the solenoid failed prematurely, also not sure if the solenoid he bought from Amazon was the right one. Or the replacement he bought is either to be honest. Early this year everything stopped working. No weld, no power to the outlets, so he brought it to me and I found out it had worn out brushes. Fixed that. Looked at his solenoid and told him that I thought it was wired wrong (because it was getting pretty warm) or was the wrong part. The solenoid has three wire connections and the machine has only two wires going to it (both black wires and no numbers). When I see a fuel solenoid with three connections I always assume ground, pull and hold. These solenoids are labeled pos, neg and aux. So he took the trailer and said he would bring it back for me to figure out if/when the solenoid failed. He brought it back a couple of weeks ago and I got a chance last weekend to dig into it. In the time between I have been wondering about the solenoid setup (why does a gas engine have a fuel solenoid?). And the way I understand it is that the outlets are meant to run at idle (60hertz) and full throttle is for welding. Also there is an auto idle switch, so there is a "load sensing" function that will idle down the engine when you stop to scratch your butt or answer the phone. Remember that I am still thinking that the three wire solenoid is pull, hold ground and the unit only has two wires going to it. Both of them are supplying 12 volts when you flip the switch to "weld". So my thought was to manually bring the engine to full throttle and see if something changed (and then maybe wiring in a ground). And it did. One wire lost voltage (so i assume this is the pull circuit)and the other still had voltage (assume this is hold circuit) So I wired in a ground to the battery, wired " pull" to positive, and "hold to aux. And it worked for about five cycles of switching from weld to power. And then stopped, I didn't even get a chance to see if auto idle was working. Now I am not getting any power to either wire when demanding full throttle. I need some help or at least someone to tell me where I messed up.
Miller used to put manuals of older welders on their site that had schematics and trouble shooting guides. You can still get them but it costs $15. Just need the model and serial number. You could also do some searching on the welding web. There may have been someone else with a similar problem. I just had a Big 40 fixed that needed new diodes. $400/ea. and needing 6 wasn't happening. The diodes more than doubled in price. Thankfully the shop keeps older machines for parts and they had one with good diodes they sold me for $500. A couple hours labour and it's working properly again.
I can't really help you on the AEAD, but it sounds like it works about like my old Bluestar 2E. That thing welded awfully smooth for as old as it was. They were quirky about the electric side though. I didn't know until just a few years ago that the "ac" outlet would only be 120v 60hz if you were in the power mode and fine adjust set to 100. The outlet would still be hot in weld mode, but I think it was DC volts which was fine for a grinder, but not much else. I guess one too many times of running out of gas and forgetting to turn off the run switch burned up the ignition solenoid and those things are very hard to find for the Tecumseh OH160. I loved the nice, low 1800rpm engine. Maybe, someday when I have more time I'll follow one of those videos for converting an automotive coil to it. I had to have something more reliable so I greatly upgraded to a Lincoln Vantage 300. Now, I have 120, 240, and 240 3ph any time the engine is running.
I found an owner manual online when I had it in my yard last time, so I printed it out and gave it to him when he came and got it. But he lost it. His son printed one out for me but I don't know how accurate it is because it says "Effective with serial no. Jf916666". I don't really understand what that means. Does it mean that it is effective up to that serial or from that serial? But, man, owners manuals were ridiculously awesome back then. My grandparents had (I think ) a 1978 Bonneville and the owners manual had so much info; spark plug gapping, valve adjustment and stuff like that. Modern owners manuals to cars for the most part might as well just be a small card with the words " call the dealership".
But this thing, wiring diagrams, parts lists, trouble shooting, I am actually surprised that it doesn't have full instructions on how to actually weld. So I was looking through it for the last night and I have a couple of ideas. Apparently behind the control panel there is a circuit breaker for the idle control. In my mind that makes sense, my thinking is that the circuit has not been active in who knows how long (and might have been wonky even when it did work) that the five times I used the throttle function was all the breaker could take. So, when he brought me the owners manual he also brought me keys to the tool boxes he put on it. I asked him to because they are seriously in the way of doing any maintenance and trouble shooting. Just imagine having to work over one when replacing brushes. It sucked. And I need to be able to open them to take the mounting bolts out. So tomorrow, I am going to pull the tool boxes, skin the welder and check the breaker, check the switch and then try to figure out how to check the idle control circuit board. Might be posting about that tomorrow. Because, as epic as I think this owners manual is, I am not sure that I understand how to read these wiring diagrams.
I know nothing abou the AEAD Miller, but it sounds like you're describing the fat round Syncro Start type pull solenoid. If yes, you are correct, the three terminal solenoids require a timer module for the pull circuit on the Aux terminal. If you don't use that, or connect a steady 12V input to that terminal, it will prematurely fail. They do make two wire solenoids, positive input signal and ground, don't know what part number you need though. One thing important about those pull type solenoids, both two terminal and three terminal, when the solenoid engages and pulls in, the plunger has to pull all the way in and hit bottom. If the linkage adjustment prevents it from doing that it will smoke the solenoid.
I think it means starting at that serial number. If the machine is from the 70's or later the the first 2 letters are the year starting in 1974 I think. I've seen 1971 and 1972 machines that have 71 and 72 prefix to indicate the year. 1973 started with an H (1970's) and then a letter for the year D. A Jan. B Feb. C Mar., etc. They didn't used vowels. Should still be able to find a serial number list online. J is 1980's and K is 1990's. As far as manuals we bought a 1953 GMC 3/4 ton or 1 ton (single wheels) for $150 at an auction. It had a wooden grain box. The guy that drove it home for us said he could steer with one hand. It ran like a top! It even had the original owners manual in the glove box! It told you how to do all kinds of stuff like adjusting valves and other stuff unlike newer manuals that just tell you to take it to a dealer.