Need help Miller blue charger on 89 truck w skyhoist

[gisign]

My truck's been sitting for awhile. Cranked it up today and the crane wouldn't work. Checked the two batteries and one had reversed polarity on the voltage. Checked the voltage on the charger/welder and am getting 1/2 volt on the charger output. Welder output is fine. Has anyone dealt with this or have any suggestions? Thanks

[bonehead]

I don't know about the reverse polarity, but I maybe can help with the Blue Charger. The switch, or lever that says 'charge' or 'weld' could have some crud accumulated on it, especially if it sat for a while. You might try switching this back and forth a few times. Sometimes dust or grease will build up on the contacts, and going back and forth might clear it up. Also, if you remove the top cover of the machine, you can find two fuses on the controls side, near the top. Check these fuses. Otherwise, there's a circuit board near the fuses which controls the charge/weld circuits. This component is a 'usual suspect'.

There was a Blue Charger for sale in this forum a while back, I don't know if it sold or not. If all else fails, You might do a search for it.

Good luck with it.