Dusty engine bay showing alternator and an ALT relay

Alternator Full-Field Relay

This relay is wired so that, when the key is in RUN, and the winch is pulling IN, the alternator is forced to its maximum output, even if the voltage regulator fails.

I also have the relay's NC terminal (87a) wired to a short jumper wire so I can force the alternator to full-field without the winch.

For more info, see this:


Note that there are only 2 vent holes between each pair of ribs on the front of the alternator case (above L of the pulley) indicating that this is a large-frame 130A 3G. A small-frame 95A has 4 holes.

Owner caption July 2011 · Photo 3791 of 5000