I have a Sun tach that I want to put into my 81 4X4. I know how to wire it, but the tach light has me puzzled. With the way the Toyota's are wired, the light fuses are hot, and the light switch is the ground for the circuit, and they run through a relay. The light in the tach is grounded by the same wire that grounds the tach. How do I hook up the light? I guess I could modify the tach light wiring, and add a stand alone ground to it. What have you guys done? Thanks, Dean

 

I figured it out. I was thinking about it all wrong. The relays put juice to the wires that go to the lights. I'm wiring it into the wire that feeds the dash lights, so it will work with the rheostat the controls the dash lights brightness. Dean