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Weird Miller Air Pak welding machine problem!

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  • Weird Miller Air Pak welding machine problem!

    I recently purchased a 1988 Miller Air Pak 400amp welder from a government surplus auction and it has me stumped. The unit has the Deutz FL4912 diesel motor, which runs perfect. The problem comes from the generator side of the unit. When I fire it up, the unit produces 110v power but not 240v. Also, when it is not supplying 240v power I am unable to strike an arc. If I let the machine sit and run for several minutes (sometimes close to an hour), it will eventually begin supplying power. Once the unit starts generating power, it functions perfect in all amperage ranges and supplies smooth, dependable power out the 240v outlets. I have cleaned the polarity barrel switch and the amperage range barrel switch so they are all making good contact with the associated plates. All of my connections are in good shape, and it is wired up correctly for the 240v outlets. I even wired an aux power outlet at the outlet of the three 45amp fuses located in the junction box. Once the machine starts producing power, it works flawless as long as I leave it running. But, if I shut it down, I'm back to playing the waiting game for the unit to produce power again.Do you have any idea where I should look for a solution? I really love this unit, and it welds perfect when it is producing power. Thank you in advance for any and all help!!!~Will Courtier~