purchasing voltage regulator for pos or neg system

Ellis Kinney · Apr 29, 2011

Everyone who responded to my questions yesterday was of the opinion that all 6 volt systems for IH were pos. Ok, what about the voltage regulator? The Super MTA has been in my possession since 1992 and charging well until the end of last summer with a 6 volt neg ground system. If I buy a voltage regulator and polarize it for my system will it be ok? Since it was charging well until last summer I would rather leave it alone than try to figure out how to switch it back. Thank you for your previous responses. Ellis Kinney

gene bender · Apr 29, 2011

You can have a neg ground system just be sure the regulator is neg ground the generator doesent care but the regulator sure does.

Bob · Apr 29, 2011

The reason MECHANICAL "vibrating contact" regulators are SOMETIMES polarity-sensitive is the material(s) the contact points are made of.

MANY of the regulators I've seen these later years are NOT marked as to a specific polarity.

To save money, sometimes only one contact point of each pair is made out of "the good stuff" corresponding to polarity. In other words the upper contact in a regulator intended for (-) ground or the lower contact in the same type of regulator intended for (+) might be the most likely to erode and pit, so it's made of better stuff. (What the "better stuff" is, I don't know, copper/silver/tungsten maybe?)

If you use the regulator on the polarity opposite of the one it was intended, it WILL work, at least for a while, but contact wear will be more rapid.

Of course, ELECTRONIC VR's are a different matter and, likely, all the smoke will be let out if connected to the wrong polarity.

Anonymous-0 · Apr 29, 2011

Either way just don't forget to make for sure the ignition coil is wired correctly. On a negative ground system the - post goes towards the distributor and the + post goes towards ignition. On a positive ground system they are reversed. If you have electronic ignition then make 100% sure your polarity is set for whatever kit you have. I have converted an M to 12v negative ground and an H to 12v negative ground with electronic ignition. One last thing is if converting from positive to negative ground then don't forget to switch the leads on the ammeter or it will read backwards.

Bob Kerr · Apr 30, 2011

Most regulators are either stamped on the back or on a mounting tab stating whether it is neg ground or pos ground. Pull your regulator off and see what it says. If it just has a cut out it may be ok to run backwards, but a true voltage and current regulator will cook.

Bob · May 15, 2011

(quoted from post at 09:38:58 04/30/11) but a true voltage and current regulator will cook.

I think that's QUITE an overstatement, if we are talking about mechanical regulators.

SHORTENED life is more the reality.

Of course, if solid-state, the smoke leaks out rather quickly.

purchasing voltage regulator for pos or neg system

Ellis Kinney

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gene bender

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Bob

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Anonymous-0

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Bob Kerr

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Bob

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