MG Car Repair: 69 Midget, starter solenoid, battery distributor

Question
Hi Howard,
 I recently purchased a 69 Midget and the kid I bought it from had changed the battery, distributor and coil.  I asked him if he checked initially if it was a positive or a negative ground. He wasn't certain but attached it negative ground.
  My questions are, how do you check if someone had installed it properly or not?  What or if it will damage anything if attempted to start improperly installed?
  I'm planning on getting rid of the points and installing an electronic ignition.

 Thanks,
D'Ramises

Answer
Hi D'Ramises,
The 69 Midget was negative ground. Look at the ignition coil to see if the terminals are labeled (+) & (-). The (-) post should have the white with a black tracer. I can't think of a reason why anyone would have turned the polarity around like the older cars were. They would have had to repolarize the generator to do that. However, just to play it safe here is how to tell. You need to remove the generator belt and unplug the two wires on the generator and get a heavy gauge wire (12 ga. long enough to reach the starter solenoid) and attach a smaller short wire (14 ga.)to one end. Now, attach (however you can) the small 14 ga wire to the small spade connecter on the generator and the 12 ga wire with the small wire attached to it, to the large spade connector on the generator. Now touch the other end of the 12 ga wire to the hot battery cable on the starter solenoid and watch the generator pulley. It should turn like a slow electric motor in the direction that the engine turns. Hold it on for several seconds and remove it and do it again. Each time the generator should rotate in the same direction as the engine turns. It is now polarized for the way the battery is installed (negative ground) and is safe to connect back up and run. If it were polarized the wrong way and you had started the engine, it would melt the wiring to the generator and maybe the generator and regulator too.
Good luck on the electronic ignition. They are less maintenance but if it fails in the middle of nowhere, the man who designed it could NOT fix it.
Howard