The truck came with a 95 amp Bosch alternator that had a W terminal for hooking up to a tach. The internal voltage regulator quit me just as I was leaving Fort Nelson BC last year and there were no parts available in that part of Canada. No regulator, new alternator or rebuilt one. The output wire transfers current to the battery and is typically brown in color. The sensor terminal monitors voltage output, and the indicator receives voltage from the ignition switch. Along with the battery, the alternator produces the electrical power needed to operate both the electrical components and engine of a vehicle.

Ah, you're likely to get a whole variety of answers from people here about what they think you have in your hands. I recommend you get an oscilloscope and measure what this terminal will do across a variety of different alternator speeds and loads. Alternator Terminal Identification Guide. The following information is presented as a guide when wiring and troubleshooting alternators. Terminal Definition Notes A BATTERY Comes from the word ‘Accumulator’ B BATTERY Main Battery Feed B+ BATTERY Main Battery Feed C CENTRE Neutral, ‘Half-Voltage’, centre point of a Y-connected stator