i am in the proscess of installing new gaffrig gauges. on the back of the new gauge it has a ''s'' which i assume means sensor a ''g'' which i assume is ground and a ''I'' which i have no idea means. is that ment for a positive line to hook up to? also my stock tach has a pole for a ground to hook up to and the new gaffrig has no ground on, it besides the one for the light bulb.

i = ignition(purple)
g = ground(black)
s = sender( pink, fuel level)
(grey , tach )
(tan, water temperture)
(blue, oil press)
(brown, oil temp)
(tan w/blue tracer, alarm trigger )

thanks! that was a big help

The tach only uses the one ground, instead of two like the little ones.

The post above gave you the correct configuration for wiring.

my stock vdo tach had a big ground wire on it. should i just hook the ground wire all on the ground for the light bulb? or just dont hook it up?

the big ground probably came from the harness. assuming its a merc.it should go directly to the ground terminal on the guage. and then jump to the rest of the ground terminals on the rest of the guages, similiar to the ones pictured.

good luck

yes its a merc setup. so the big ground wire thats out of the harness is like the main ground and all the other grounds jump from each other and then hook to it.

that wouldbe correct. the large red is a cicuit breakered wire also from the harness. use it for the ignition switch hot, and maybe a stereo. alot of people use it for a hot leg for their accesories.

great info thanks alot! i will try it out tonight.

I have a Gaffrig fuel sending unit lost instructions does anyone know what wires on sending unit you jump to recalibrate the sending unit
Thanks