M1010 conversion to 12 volts

I have a pickup that has all the components of the 1010 ambulance. Two 28 volt regulators, A/C compressor, locker in front diff. I am having an issue with the battery charging, it not, 2 new batteries rebuilt alts still no charging. I have 25 volts coming off the bottom alt, nothing coming off the top. I did get the alt checked again it is putting out 28 volts at 105 amps on the bench. The wire that attatches to the output post does not have 24 volts going in, I visually checked the fusiable links they look ok. Do I have a bad voltage on the drivers side, blue box. If that is it I found a new one but the guy wants $500 for it. I thought it might be easier to convert to 12 volts.

I do have the conversion for the blazer as I converted mine. I also have a spare 12vot starter. Does anyone have the instructions on how to convert this system.

Thanks,
Chuck

Hi chuck
From your explanation, it might be those fuse links, Fuse links can look OK but you have to ohm them out. Also ohm out all the wiring in the system. You want to make sure all your connections and wiring is good before you come to the conclusion that you have a bad part. Check every from the power source to every ground wire. I’m not familiar with that particular electrical system but to trouble shoot any electrical system is to eliminate the obvious.