[TR] Positive Ground It Is!

[Jeffrey Gayton]

Thanks, Randall. As you've probably gathered from some of my posts, nothing is
too obvious for me at this stage!

> On 12 Sep 2014, at 3:35 PM, Randall <tr3driver at ca.rr.com> wrote:
>
>
> ---- Jeffrey Gayton <jtgayton at icloud.com> wrote:
>
>> But at Dave's suggestion, I took a closer look at the battery and found
>> markings behind the posts. I've got a positive earth car! Thanks again for
>> everyone's help. Now I can order some LED tail lights.
>
> Apologies if this is too obvious for words: Now would be the time to
consider whether you want to stay opposite to the rest of the world or convert
to negative ground.  We're fortunate to have Litezupp that makes positive
ground LED bulbs; but the vast majority of aftermarket accessories are
strictly negative ground.  Even just adding an outlet to charge your cell
phone is extra hassle with positive ground.
>
> I once saw a buddy burn up the wiring harness in his MGA, because it didn't
occur to him that the CB radio he had borrowed had a (negative) ground path
through the antenna clamp.  It worked at first, because the bumper bolts were
too rusty to conduct.  So we were hundreds of miles from home when the one of
the bolts rubbed through the rust and the cockpit filled with smoke rolling
down the freeway.  You might say it made an impression on me!
>
> The conversion from positive to negative ground is pretty trivial on the
TR2-4.  Just swap the wires at the coil, ammeter and battery; then repolarize
the generator.  If you forgot to swap at the coil, you'd probably never notice
the difference.  And if you forget to swap at the ammeter, it just reads
backwards.
>
> Repolarizing the generator sounds scary, but it's trivial as well.  Just
pull the wire off the 'F' terminal at the control box, and brush it against
the 'A' terminal next to it.  You'll see some small sparks to tell you the
connection was made.  Then put the wire back on 'F', close the hood and take a
drive.
>
> - Randall




-- Jeff