Diemma, 6 Or 12 Volt?

[Shadetree]

Here is the dilemma, I thought I had it figured out. I had decided to leave it 12 volts and go with an alternator but with a positive ground because I am considering changing the original gauges to 12 volt. But I still need a positive ground; I have negative ground right now with aftermarket gauges in a frame below the dash. The original gauges are intact. Mac's has the conversion kits to an alternator but not to a 12 volt with a positive ground.

I have read the past threads on this but couldn't come up with an easy solution.

Can the gas, temperature, fuel and amp gauges be changed to negative ground? I would like to keep the gauges original but I really like the 12 volt alternator conversion. The truck is in its original configuration except it has a rolled and pleated seat and carpet.

I could easily go back to 6 volt by changing out the battery, headlights and taillights.

What to do? Give me your thoughts.

Thanks

[mrtexas]

Yes, no need for positive ground. Gauges can easily be changed. I just did it. Too hard to find a battery that fits for 6v. Buy the alternator locally. I got my rebuilt one for $55.

[Vic Piano]

Bud, the stock gauges will work on negative ground 12 volts, all you need is a voltage drop unit; you can get one for all the gauges or hook each gauge up to an individual reducer.

[G.M.]

You can use an alternator for 6 or 12 volts pos or neg ground IF. If you want 12 Volt neg ground you have to change the polarity of the diodes or the way they are hooked up. You can take any 12 volt alternator and remove the diodes and voltage regulator. Install diodes forming a bridge rectifier with reverse polarity. Transpo makes a small series of adjustable voltage regulators that you can control the voltage output to a 10th of a volt with a small screw adjuster. If you use a 12 volt Delco alternator get a 24 volt stator and on 6 volts it will charge at lower RPM's with a standard Ford pulley. You can buy reverse diodes and 6 volt regulators for the Delco. I made 7- 6 volt pos ground alternators that fit in the 39 generator shells for my own use. I used a small Nippendenso 12 volt and my own reverse polarity rectifiers and the Transpo 6 volt adjustable regulator. The diodes and regulator are mounted in the rear brush cap and is a plug in unit for easy repairs, it plugs into the rotor and stator. In several years of use no repairs required. I have them adjusted to Slow idle at 6.75 and at anything above Idle at 7.60. These look just like the original generator. Even without the alternator I see no need on a stock old Ford for all this 12 volt foolishness. Some call it an update????? G.M.

[41ford1]

X2 on Vic's comment. The gauges don't care about polarity. They just need 6 volts. The guages in the pickup are stock. Each one has a "Runtz" reducer. Most of the vendors are selling a reducer that will service the whole cluster. That makes it very easy to run them in a 12 volt system. If you are already set up neg ground don't bother changing it.

[Planojc]

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After installing a 6 volt pos ground alternator from Macs, in my 51 about a year ago, I am now convinced that there is no need to change over to 12 volts. My B.W. overdrive kicks in every time now and I saw an improvement in the headlights. Also by staying 6 volts there is no need to mess with the gages or changing lamps.

[Henry/Kokomo]

I have a setup as described by 41ford1 which has worked perfectly for four years. The Runtz conversions aren't the cheapeast but they seem to perform admirably. I don't think you'll ever be sorry if you install an alternator (if you do much driving). Got mine from Patricks and its done well. Good luck.

[gmc1941]

Check out the "SEARCH" converting from 6 volts to 12 volts many fine articles(threads).

[rotorwrench]

I've always been a firm in keeping the 6-volt but I always wonder if reproduction manufacturers will keep making the 6-volt bulbs. The sealed beam fog or driving lamp bulbs are already getting hard to source and some spot lamp accessory bulbs are also hard to source. The quality on some of the reproductions is not so good either.

[Shadetree]

Many thanks guys for the super responses. I just ordered a 12 volt negative ground alternator with the slingshot mounting bracket. Although it is not original equipment it is a simple and reliable source of electricity. My truck was already a 12 volt negative ground voltage system from the previous six cylinder engine. The good news is I can make the original gauges work if I wish.
Thanks again, I appreciate your honest opinions.

[mvonhobe]

So rotorwrench, would you please provide some sources for 6-volt bulbs, lamps, light?
Thanks!

[mrtexas]

Originally Posted by Shadetree

Many thanks guys for the super responses. I just ordered a 12 volt negative ground alternator with the slingshot mounting bracket. Although it is not original equipment it is a simple and reliable source of electricity. My truck was already a 12 volt negative ground voltage system from the previous six cylinder engine. The good news is I can make the original gauges work if I wish.
Thanks again, I appreciate your honest opinions.

Your intake might not work with an alternator depending on the year.

https://sites.google.com/site/mrtexa...e/36fordintake