Gauge Operation Negative Ground.
 

There is an excellent post by JSeery dated 4/6/2015 concerning gauge operation. After reading this information it appears to me the the gauge operation is unaffected by a change from positive to negative ground. Is this conclusion correct?

Re: Gauge Operation Negative Ground.
 

Yep, the gauge doesn't care about current flow direction. If you go to 12v negative ground all you need is the voltage reducer. That is what Ford did when they went to 12v, they used the same basic gauge system with the addition of a voltage reducer. Many now prefer the Runtz units (one required per gauge).

Re: Gauge Operation Negative Ground.
 

Great! Thanks for the quick answer.

Re: Gauge Operation Negative Ground.
 

Mr. Seery did a great job of explaining gauge operation. The only thing is that when i changed from 6v to 12V on my 40 Ford the BATT gauge (which is really a voltage gauge)
I had to isolate the BATT gauge so it operates as a single gauge and use a 60 ohm resistor in series with the 12V input to the gauge so gauge will read properly.. Read about it here:https://www.fordbarn.com/forum/showt...olt+conversion

Re: Gauge Operation Negative Ground.
 

Very true, some years have the loop type ammeters which just require you reversing the direction the main power wire goes through the loop. Other years are as 19Fordy posted.