14. The dimmer switch hooked up to where the stock tripmeter was housed. There are a total of six orange female wiring ends on the back of the dimmer, four hook up to the white male ends on the fuel, oil, temp, oil pressure, and voltmeter gauges. The other two female ends hook right into the back of the tach and speedo gauges. To hook up the dimmer's power, Doug plugged in the last connection into one of the unused power connections from the stock gauges.