Ben wrote in news: snipped-for-privacy@p7g2000yqd.googlegroups.com:
The black/white wire goes from the starter to the starter relay under the dash (becoming blk/red) then (blk/wht again) to the ST terminal on the ignition switch. The starter relay is energized by the clutch interlock (blk/blu) at the clutch pedal.
For some reason, your solenoid isn't being sucked closed by battery current. There are several possible reasons for this. It would help very much for you if you had the EWDs, which are still available at Honda's Techinfo site:
I'd like to eliminate the solenoid as the source of the problem, but that will take a bit of patience. Remember that jumper wire you used to test the solenoid? Take that with you everywhere. Next time the key does not make the starter operate, don't try more than two or three times, but use the jumper wire from under the hood instead.
If the starter occasionally does not operate /even with the jumper/, then the solenoid is flaky. If the starter operates with the jumper but not when the key is used, then the ignition switch may be faulty. It's 21-years-old, remember. See this page:
I have to say that 13.5V charge is acceptable, but on the low side for a Denso alternator. I'd be expecting 14V even with all accessories on. Your alternator isn't outputting what it should.