Classic/Antique Car Repair: Triumph TR 6 ground, triumph tr 6, magnet field

Question
Is a Triumph TR6 a postive or negative ground? I just purchased one that had been in storage for 10 years without a battery and the owner couldn't remember.

Answer
Hi Roger,
A genreal rule of thumb on any British car is that if it has an alternator it is negative ground and if it has a generator it (WAS) positive ground. The reason I say "was" is because on a DC generstor you can easily change it to negative ground by reversing the battery leads and applying power (+ now) directly to the armeture and field post for several seconds while the engine is stopped. You do this several times. Then reverse the leads on the ignition, fan motor and any other motor with a permenent magnet field. If it has an amp meter they must be reversed also. I did this many times in the dealerships I worked in because aftermarket positive grounded radios were hard to find.
I have never seen a positive ground alternator.
I think most US version TR-6s were with alternators.
I hope this helps,
HMF