Hagen Brothers farms,Goodrich ND | I have no knowledge of that truck model, but will take a poke at it from the information in your post.
Do I understand it that the batteries were connected wrong, pos ground instead of neg ground and you connected the batteries correctly ?
And that most polarity sensitive things like gauges now work ?
Some heavy truck alternators are built with floating ground, in that the negative and positive outputs of the alternator have separate posts so they can be connected to work either pos or neg ground just by connecting the ground and hot cable to the appropriate terminal.
Most lighter duty alternators use the alternator frame for one electrical output terminal, so are built as pos or neg ground only. In that case, some parts, rectifier pack, diode trio , regulator, need to be the correct parts for a given ground polarity.
Normally if you swapped the ground polarity by switching battery cables without changing anything else, it should have caused an a dead short in an alternator designed or wired for the opposite polarity. This should have caused heavy sparking when you connected the last battery cable and should instantly burn out the alternator rectifier pack.
The exception would be if the truck wiring has a fusible link (a type of fuse) in the alternator output wire.
Either way, if you changed the electrical system polarity, you would have to either reconnect a floating ground alternator to the correct system polarity, or replace / rebuild a fixed polarity alternator to the correct polarity now used.
Using a test light to see if the heavy alternator output lead has power at the alternator, will help determine if a fusible link or the alternator rectifier pack was blown by reversing the polarity. |
alternator from positive ground to negative ground
