Electrical problems (it appears like this) can be expensive to track down. It is a combination of experience and luck on how much you spend. The problem is you did not spend much likely and you may well exceed its value in short order.
Set an upper limit between tows and mechanic hours and go from their.
DO I have this right?
You brought it to the new mechanic, the both of you talked about the possibility of it being the clutch safety switch, but instead of replacing that, he replaced the starter?
Why the heck didn’t he replace the smaller, cheaper part FIRST???
Or at least, chance it at the same time?
When he does the clutch switch, have him do the ignition lock, too.
BC.
If this problem continues to be erratic, I would suggest a mechanic install a couple of 12v test bulbs/LEDs at a couple of places in the wiring tree. One at the starter solenoid wire, and maybe the other one on the input to the clutch switch. The mechanic may know then which component is not transferring the voltage.
When it does not start, write down which bulb[s] is/are “on”, indicating good voltage.
Radio Shack sells small 12v. LEDs; other parts stores sell sealed colored bulbs that would work.
If you install a bypass switch as previously mentioned, make sure it is inside the car. Underhood switches can be dangerous for you could start the car in gear and it would run over you or another person.
This sounds very similer to the problem I had with my 94 Jeep Grand Cherokee. What we came to figure out after replaceing the starter, the battery, the batery cables, the ignition switch and all fuses that needed swaping out, was that it was more then likely an ingnition relay switch somewhere along the “tree” of wires. What we did to fix this problem outside of replaceing all wires was to bypass the ignition and installed a button right to the starter. The key turns on the power and the button starts the Jeep. What we figured was the problem with the loss of power was because when it wouldn’t start we would keep turning the key hopeing that there was some chance that it would mariculously start yet all that did was slowly drain the battery. After installing the botton we never had starting issues again