This plug is hot in run. It supplies power to a supplemental fuse box, which powers the O2 sensors, e-fan, aftermarket gauges, and fuel pumps.

The tan colored wire (the left most wire in my hand) is actually the stock pink "resistor" wire that supplies 6v to the coil. If you are upgrading to HEI (or an aftermarket ignition) that resistor wire is the one that needs to be bypassed.

Owner caption September 2011 · Photo 3 of 40