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Big 40 Question

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  • Big 40 Question

    I traded a diesel engine from a wrecked truck for this Big 40. The outside looks great, and it ran great. The seller overhauled it, putting a new front on it, so I donít know what the serial number was. When they were refinishing to sell it, some parts got more attention than others, and they practically spray painted the entire guts, wiring, etc. I am trying to diagnose an issue because now because it wonít start. I plan to get a new battery. The alternator is new. I stick the key in and push the button, but I here a small click, and nothing; once it clicks once, it wonít click again. I welded with it the night he dropped it off, so I know it has worked, but the wiring looks rough. I want to get a book for it, and I have been trying to locate engine info. He said someone told him it was a 76. All I know is that that the engine has CWC F400A-612 on the bottom, and the top has F400A-531. Can anyone tell me anything about this welder? Does the starter sound bad? How can I find out what year it is, etc.? Many thanks for any assistance. There's also another number K156. I didn't take a picture of the top of the engine. I tried to upload pics of the welder, but it says they're too large. Name:  24c970164ebe88464b5465db56f2d144.jpg
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  • #2
    Big 40 Question

    The clicking noise leads me to believe its a bad starter. I'd check all the wiring involved with it, positives and ground. Use a voltmeter or test light to make sure it's getting power. That's where I would start, but then again I'm a welder, not a technician....I hire people to fix these problems for me. Lol


    • #3
      Try tapping on the starter with a small hammer lightly when my startere went out in my truck I had to do that for a couple months. It would click then nothing turn it off then click and nothing.


      • #4
        Big 40 Question

        The clicking noise is the starter cylinoid. You should have a cable from bat to starter then on from push button. If both are hot it is either a grounding issue between the starter and the frame or your starter is fried


        • #5
          I appreciate the help. I figured something may be wrong here. I've pulled the enclosure off, and I've noticed that some of the wiring either looks old or halfway put together. They had a wire spliced into this starter wire to the volt gauge, and if you wiggle it, you can either have no battery juice or some. I didn't want to rewire the entire thing, but some it needs major attention. I still think the starter is old, and they spray painted over the ground, so it may be losing some of its connection there. I simply want to identify the year too. i know its got to be a 70s model, but the Big40 manual on Miller's site is a 1984 and the machine looks different. I don't know if the specs still apply. Finally, since the shell is off, I can see the Amperage dial, the larger hand one on the left. When you look at it from the back, you can see where the contacts are supposed to line up. As you turn the handle on the front, the internal dial turns, and it lands on the copper connectors, but it's not flush on them. Should it be completely flush, sandwiching them, or is it fine as long as its touching the side of them--at least making contact at all?

          Since I don't have a manual and part numbers, any suggestions for the fuel tank. it looks great with the fresh paint from the outside, but I noticed the inside is pretty rusted. Any tips on draining and refinishing or installing a new?



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