What am I looking at? An old alternator voltage regulator? Used way before my days of tinkering and haven't seen anything like it. The alternator is a three wire rebuilt this spring. Am I correct in saying if it was the old 5 wire system it would have used this regulator{?}? I haven't unwrapped all of the wiring yet, but I'm guessing that since the Alt has the three wire set-up, the wires to the regulator(?) were cut and the part just not removed from the firewall? (You'll have to flip your monitor because the stupid Apple pics won't stick upright . . .)