"I was thinking that oxidation/corrosion in that fuse holder might be the source of intermittent problems, which it sounds like we’re dealing with here."

I was thinking the same, as it is a no-start some-times. As in my notes on the web page, I mostly found this trouble with the cars where that fuse was moved back inside the car at #6 (1991-93) going against the common thought the placement on the fender was the design error. But that spot inside has its own set of issues.

The method I describe with the test light is effective at sorting those troubles where the corrosion or oxide provides a variable high resistance, variable over mechanical stress, time, and temperature. The mechanical part of contact resistance is what we see when a wire is jiggled or a terminal bumped, so I'd try to watch the test light while shaking the red wire or tapping on the FI relay housing. The latter might be a two-person trick, or something I do alone with the help of a piezo buzzer.

However, if the intermittent trouble isn't currently showing itself, the test lamp could be left in place until it does, providing an instant indicator that the main fuse and its circuitry is intact.




--
Art Benstein near Baltimore

It appears autocorrect has become my worst enema.