# After market tach wiring 1969 GTO



## LibertyBlue69GTOConv (Oct 25, 2009)

I bought this after-market in dash tach for my 69 GTO back in the 90s. I've lost the instruction sheet, and I want to make sure I install it correctly. Out of each tach light it has a blue and a black wire. The blue ones get joined together, while the black ones have separate connectors. See attached picture. Does anyone have ideas for where the blue and black wires go? I assume the black wires are grounds, and the blue one connects to the wiring harness, but would like to make sure so I don't do damage.

Thanks in advance for your help.


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## RunninLeMans (Apr 3, 2014)

The wiring to the lights should be just ground (black) and lighting circuit (blue). Are those two wiring posts near the top? Mine had two posts marked '+' and 'S', the "+" goes to switched power so it comes on when you have the ignition in the on position, and the 'S' goes to the negative side of the coil with a 2-amp fuse. In addition, I had to ground the casing to the dash as the mounting points were plastic and didn't ground. This may be completely different from yours, just sayin'...


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## LibertyBlue69GTOConv (Oct 25, 2009)

The post on the top of the tach connects to a plug, out of which comes a long brown wire (which i presume goes to the negative side of the coil, though, curiously it is not a fused wire) and a red wire, which I'm guessing plugs into the fuse box somewhere for power?

Thanks for answering. I guess I can find grounds on the back of the dash somewhere for the black wires. Still not sure what to do with the blue wire.


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## RunninLeMans (Apr 3, 2014)

I added my own in-line fuse, the manufacturer said 1 to 3 amps was fine. Lights just get power and ground, so the blue wire should just go to any light circuit, similar to other dash lights. Don't be confined by the connector, since it's aftermarket, it probably doesn't have an assigned spot in your wiring harness.


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