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MG MGA - Rebuilt control box


Hi guys,

I recently had a voltage regulator for a '59 A rebuilt with modern internals. The place that did the conversion marked "negative ground" on the inside of the plastic cover. Would I necessarily have to change the car to negative ground for this? There's no radio, and I didn't plan on installing one.

Thanks in advance.
Dave
David Plantz

Not knowing what type of electronics are used, I would not ignore the warning on the cover. You should contact them to see if it can be used with a positive ground system, but I tend to believe not, or else why would they put the warning about negative ground on it.
Ed Bell

Hi Dave. If the sticker says negative ground, I would most definitely heed that warning! Mordern electronic parts are often polarity sensitive in the extreme. Connecting this regulator to the wrong polarity will likely fry your brand new regulator, and could possibly cause damage to other electrical components. Im with Ed on this one, call the people who did the regulator conversion and get the details on what you need to do to install the new regulator without causing damage. Cheers, Glenn
Glenn

Send it back and have them do it the way you wanted. Unless you specified the conversion they either shouldn't have done it or at least asked if you wanted it done.
Del Rawlins

Geez, they should have at least written you a note on this. I'd call to ask for sure, then tell them they should include neg conversion instructions for the next guy. If you're still not clear on the conversion, we can help.
Tom

Unless it worries you or you want the aggravation, I'd just live with it. Barney provides instructions for easily switching polarity, and unless you have a fuel pump problem, it's not really worth having a fight over.

dominic clancy


Yes, I wasn't happy that they didn't tell me that it was setup for negative ground. I called the guy who updated the control box and it is in fact to be used with negative ground. I didn't ask for it that way, but I've already repolarized the generator and put in a single 12 V battery. Probably easier for me to just run it like that.

Now it seems my replacement starter switch is defective. I'm ordering another this week, so hopefully I can see how the new wiring harness is going to work next weekend.

Thanks to everyone who offered suggestions.

Dave
Dave Plantz

I disagree. You shouldn't have to modify your car in order to use what amounts to either a defective, or incorrect part, depending on how you look at it.
Del Rawlins

You should switch the positions of the 2 low tension wires on the coil.
Tom

This thread was discussed between 03/02/2007 and 06/02/2007

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