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MG MGA - Negative Earth

I know this may be old hat stuff but is there a big deal in converting the A Roadster to negative earth and specifically what has to be changed? Also whats the advantages?
c allen

If everything is stock all you do is switch the battery around 180 degrees. The advantage is that you can add modern electronic things (like a radio). If you don't want to install those things than there really isn't a reason to reverse the polarity.
Darian Henderson

You just have to switch the primary wires on the coil, and polarize the generator after changing the battery leads to neg. ground. Unless you have electronic ignition or an electronic fuel pump that is polar sensitive. The advantage is that it allows you to install modern electrical components into your car. You can then also install a lighter socket for cell phones,etc. without having to isolate it.
Ed Bell

All is true if you are running a concourse MGA. In that I don't mean show car, I mean - as it left the factory. A couple of things that might be an issue: 1) if it was previously converted to electronic ignition or b) if the SU fuel pump was relaced in , oh say, the last 10 years. In the case of the fuel pump, the use a catch diode is common to extend the life of the points or even if it was converted to electronic points. IF it has the diode, it can be reversed to make it work in a neg ground situation. I have recently seen adverts for non-polarity sensitive fuel pumps.

I can't think of anything else that might slow down the conversion. Oh yeah - one more: if you have an original pos ground radio.

Chuck
C Schaefer

Gentlemen: While I am a TF owner, I regularly check the A Posts, just to see what you "modern" guys are up to. Do your comments as to negative ground also apply to TFs?
RUSS YOUNG
D R Young

Unless you want to put fancy schmancy electronic gizmos in your TF (or MGA), there is no reason to mess with it. It's just adding one more unexpected variable that might come around to bite someone who didn't to a scrupulous audit of the car befor working on it.
David Breneman

question? i know NADA about electronics!!!!
how do you determine if your MG is positive
or negative ?
gei irwin 1

Dave B is exactly right, there is no real reason to convert the car to negative ground unless you are planning to put a modern radio/sound system in the car. everything else can be run from an auxiliary power outlet that can be purchased from most marine outlets, such as Boater's World and easily installed in an out of the way place. With one of those installed you can plug your cell phone charger, GPS or laptop into it - just be sure that the case of the device is not at ground potential (99.9% of the devices today have the power completely isolated from the case). IF you do decide to go ahead and convert the car to negative ground, do yourself and and future owners a favor and get the NEGATIVE EARTH stickers from Moss Motors and install them per the article on my web site, SU Fuel Pumps and More at: http://homepages.donobi.net/sufuelpumps/ Click on Other Tech Articles and then on Negative Earth Stickers. Cheers - Dave
David DuBois

gei irwin 1
Check which battery cable is connected to the frame of the car.
+ is pos ground
- is neg ground
Kris Sorensen

This thread was discussed between 24/02/2008 and 25/02/2008

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