Re-doing my F6 COE. I have a new OEM style wiring harness, and an immaculate OEM instrument cluster that I want to use, and I'm tossing the 6 volt system. So, my question for the experts is this:


Will the original stock 6 volt positive ground instruments (gas, oil, temp) work correctly on a 12 volt negative ground system using a voltage reducer, or would I need a 12 volt positive ground system also using a voltage reducer? (I know the starter doesn't care).
The people that sell alternators seem to think polarity doesn't matter, but I think it does.

 

The gauges will work with either positive or negative ground. Dropping the 12 volts to 6 volts with the reducer will protect them. Remember to run the wire through the loop on the ammeter the other way when you change the polarity.

 

Answered my question perfectly.


Thanks

 

I restore vintage tractors as a hobby.
Most pre-50 tractors were positive ground, and at some time during their life had a 6 or 12 volt battery installed with the ground being negative.
None of the operating systems know the difference. If an old voltage regulator is in place, you need to "flash" the field coils to ensure the generator and regulator will charge the battery.
So use a drop resistor and you'll be good to go.

 

Thanks, good to know. The alternator I'm going to switch to will have an integral regulator.

 

Another reason to go positive ground is if you intend to use any LED lights. Most of them are polarity sensitive, and won't work with positive ground. You can find a few that are not polarity sensitive, but they are pricy because they have a full wave bridge rectifier built into the lamp.

 

Sorry, I meant to say reason to go Negative Ground in my previous post.

 

No problem. I understood.

 

good info in here. I think there is a 12v conversion write-up somewhere on this site. Ill see if I can find it.

 

https://www.ford-trucks.com/forums/1...onversion.html

https://www.ford-trucks.com/forums/1...nd-rewire.html

 

Thanks guys. I'll post some pics in a new thread when I get started. New alternator should be here in about a week. 63 amp Delco 10Si one-wire, self exciting, neg. ground with a A203 pulley. I bought the full Dennis Carpenter OEM wiring harness, so we'll see how it goes.

 

You should be pretty well off since you are using good parts.