Thread: Gauge 6v to 12v HELP!!!!!

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I am trying to run a gauge cluster from a 1950 Studebaker in a 12v system. The problem I am hearing now is that the Stude gauges were 6 volt +ground, and now I have a 12volt -ground system. The gauges are Stewart warner gauges in a 5 inch cluster. I am only doing the temp and fuel gauge. What can I do to make these work on a 12v - ground system. Any help is appreciated.

Well, I'm no expert, and it's been a bunch of years since I've done one of the 6 volt to 12 volt conversions, but let's see what we can do to get you started, maybe someone else will chime in with better info.

First of all, buy a Runtz 12 volt to 6 volt converter from Speedway for each gauge to drop the voltage. As I understand it, gauges are NOT polarity sensitive, which means you can hook up the positive lead right to the old negative terminal an it will work fine. The only exception is the Ammeter, on it you have to reverse the + and - for it to read properly.

Like I said, I'm not 100 percent sure about the polarity sensitive thing, so maybe someone else can help.

Don

Thanks itoldyouso, I had seen those runtz reducers and wondered. I hear from the speedo repair guys it does matter about the positive ground. They are telling me it will ruin the gauge if I do it this way, wonder if they just want the business. I just want some cool old gauges, and dont want to spend tons of cash to get it working. I was hoping someone else had done it successfully? If I dont get any other replys, I'll let you all know what happens after these voltage reducers show up. I just might have a nice looking set of gauges for sale!!

if you are worried about the pos ground.. just isolate the gauges from ground and hook them up the way they were designed... I would use a Mopar solid state reducer rather than the runtz resistor.. you can get these right from the dealership

Originally Posted by Matt167

if you are worried about the pos ground.. just isolate the gauges from ground and hook them up the way they were designed... I would use a Mopar solid state reducer rather than the runtz resistor.. you can get these right from the dealership

only problem with that is the sending units would also need to be isolated because they will now be neg grounded thru the bock on the temp and frame on the fuel side. As I understand it with a 6v pos ground car the frame was hot?

yes... with positive ground, the frame is hot.. the gauge should be able to be hooked up backwards to cure that.