MG Car Repair: 1977 MGB starting circuit trouble shooting, solenoid switch, starter solenoid

Question
Howard,
 I am a brand new owner of a 1977 MGB and I did test drive it before trailering it home.  The previous owner told me he had just replaced the alternator but the battery may not hold the charge and may need to be replaced.  Well at home it wouldn't start so the next day i put in a new battery and and when I did I connected the new battery neg term 1st...well bad idea I know because when I attached the positive lead I touched the frame with my screw driver and shorted the thing with a big spark.  Now the starter will not turn over the engine and the lights will only sometimes turn on.  When I turn the key the starter relay makes a lot of noise so I replaced it.  No help.  So I read my book it said to turn on the headlights and then try to start it I did and same thing with the occasional click or noise under the hood that makes me think I have traced down the problem and then I cannot find anything.  I was thinking of jumping the two points on the starter solenoid with a screw driver or something to rule the starter out and possibly point me at the solenoid.  I have replaced the starter solenoid switch relay and the Battery so far.

Answer
Hi Chris,
The shorting with the screwdriver had nothing to do with your problem other than damage your screwdriver and the battery cable that contacted the screwdriver.

All electrical problems need to be diagnosed like a road map. Start at the battery and follow the road map (wiring diagram)
I hope you made good connections at the battery and the ground strap.
Next is the battery connection on the starter solenoid. Tight?? Now check the ground strap from engine to frame. Tight??
Then you can go back to the solenoid. Un plug the flat spade connector (White w/red tracer wire)12 ga wire. If you have a remote starter button connect it from the battery connection on the solenoid to the terminal you just pulled the wire off of. If you don't have a remote button just connect a long heavy gauge wire to the flat spade terminal and another heavy gauge wire to the battery terminal and be sure the car is in neutral and touch the two wires together. DON'T DO THIS WHILE YOU ARE UNDER THE CAR!!! If the starter does not work than charge the battery and try again and if it still does not work you have either missed the first part I told you or you have a bad solenoid or bad starter or a locked up engine.

Let me know and we will go to the next test.
Howard