MGB LE Starting problem

I have a mint condition 1980 LE MGB with 14,000 miles that has a starter problem. The local expert charged me a ton saying something about a wire without continuity so he put in a separate button in the dash. Therefore, the starter and solenoid are obviously OK. I want to keep the car in original condition and find the real problem. Anyone have any ideas as to where I should start to troubleshoot?

I have a 1978 also in perfect condition and was having a different problem but it could be tied in. Check the innition and starter relay. Then check to see that back tail lights are grounded. Also check the two0 DIODes under the right side of the dash just above where the pasenger's feet would be. I don't know if any of these are your problem but would n;'t take long to check.

If all thst fails, you might need a switch but I would not buy one until you KNOW that is the problem. They are expensive and you don't need two!

I'll check out the diodes & relay & tail lights for grounding.

Find out what wire does not have continuity, check the connectors and the wire for faults. I would also question your experts relunctance to fix the problem as oppose to bypassing it.
Where to start looking? Go to advanceautowire.com and get a copy of the Bentley diagram for your car. If possible, make a couple of enlarged copies (this will make them easier to read and make notes on them as you check the questionable circuits). Start with the area that was bypassed. Look for corroded connectors and grounds.

Thanks KimMG. Your approach is what I had in mind. I have the nice schematic, now we'll see. Why the problem was bypassed is what bothers me.