The Stovebolt Site Forums The Shop Area The Electrical Bay help! Don't want to fry my electrical system

I have a '48 chevy 2 ton with a 235 engine. When I got it, it had a positive battery cable to the frame so that's how I connected my battery. Now after reading the posts and my manuals I think my system needs to be negative grounded, but someone said that reversed polarity will fry the electrical. My coil is wired with negative to points. Do I just change the battery to negative ground or do I change the coil wire instead?

Qualified to tell ya what to do, but I'm sure someone will be along shortly who will be!

Hy bens48bigbolt, there are a few things to change when you change ground polarity. If your ammeter was working correctly when the system was positive ground, then you will have to reverse the wiring on the two ammeter terminals if you want to convert to negative ground. You said your coil negative terminal was connected to the distributor, so that doesn't need to be changed when you go to negative ground. The last thing is to polarise the generator before you start the engine, you want to very quickly connect a jumper wire between the armature terminal of the voltage regulator (usually a large gauge brown wire) and the battery terminal of the voltage regulator (usually a large gauge red or black wire), you only need to make a momentary connection to polarise the generator, hope that helps.

"it had a positive battery cable to the frame"
was the other end connected to a battery, or did you know it was "a positive cable" cuz it was red?
have you started and run the truck since you put in your new battery?

all you have to do is switch the battery cables, the coil should be negative to the points

Bill

Thanks 3B
My ammeter was not working correctly it was showing discharge. I did not have a battery in it when I got the truck and the battery cable going to the frame was a red positive cable so someone before used the wrong cables.

Thanks red58
I assumed it was positive because it was red and the black negative cable was going to a starter that has a solenoid which I'd like to convert to the foot starter as original.

Thanks again gentlemen, that answers my concerns.

Awwwh, see, look at that, those nice boys from BC answered.