The jist: 95 Honda civic with 95 B18C1 swap and auto-manual conversion.
Car intermittently won't start. When happening dash lights up fully, main relay goes through all clicks starter solenoid clicks loudly once (as soon as I turn key) and I hear fuel pump but that's it.


At first it seemed like it only happened on hot days so I changed the main relay per my friends suggestion. No fix.
Dad though it had to be starter so he got me a new one. No fix.
Found the positive battery terminal was corroded inside, replaced with new oem. No fix.
Finally started testing things:
when I try to turn the key and not step on the clutch it lights up but nothing happens if I proceed to step on the clutch the main relay clicks and so does the starter solenoid: so not the clutch switch.
Checked all grounds and they all seem to be ok.
Checked fuses but I wasnt sure which I was really looking for.
Jumped new starter directly while problem was occurring and it started fine.

Any help welcome:
P.S. I had a coolant leak that ruined my speed sensor so I'm thinking coolant may have soaked into harness where starter lead enters harness. Can anyone tell me where on the shock tower this goes So I can test continuity. Would prefer not to cut open the loom.

 

Have you checked the signal from the ignition switch to the starter?? I had the same problem on a friends car, but instead of tracing the wire to find a fault, he decided to just wire a push button to the starter. I personally prefer to fix things back to a stock condition, but to each his own lol.

 

From what I read about the ignition switch and what it does when failing, I figured it was ok, especially since I have a door/trunk key and a separate ignition key, both oem honda, because the previous owner had ignition replaced before. But I'll probably do that tomorrow.