The Nissan Path

95 Pathfinder - intermitently, 3 dash warning lights come on: "brake", "Charge warning light", "A/T Oil Temp". (Brake fluid level is fine, no problems stopping, no dead battery problems, Tranny oil level is fine). Took it in to a dealer and they said it was caused by a common corrosion problem in the wiring harness 12" away from the positive battery terminal. (No fault codes). They supposedly corrected the corrosion issue but the alarm problem persisted. Now they say that its caused by failure of one phase (one set of diodes) in the alt and I should replace that. Just finished my personal test of the charging system with a simple multi-meter:
1. Battery alone tests 12.8V
2. Voltage at battery with engine running is 14.08 V (steady)
3. Voltage at battery with engine running, high beams & heater motor on high is 13.87V (steady)

Any ideas on what the root cause is? Anybody had any similar problems?

Classic death of an alternator, but your measurements don't seem to indicate that. Possibly intermitten failure of a soon to be completely dead alt? Could be a loose connection at the alt or the charge wire has a short. Check your connection on the back of the alt and make sure the wire that runs from the back of it to your battery isn't shorting somewhere

I'll also read up on alt failure characteristics
Thks WheatBread