# In Dash Tach Wiring



## Roqetman (Aug 31, 2015)

I'm looking at putting a used original tachometer from a '67 GTO into my '65 GTO instrument panel. First of all will it fit? And what's involved in wiring it? Is it similar to wiring an aftermarket tach or is something else needed to make it work?

Thanks!


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## Pinion head (Jan 3, 2015)

Running through the cobwebs here  the following is with a factory tach & points type distributor. IF HEI, the tach is going to have to be sent out & converted to work. 

There has to be a power feed wire, has to be a switched power source, if you had a factory clock installed don't use it's pwr wire as it runs constantly off the battery.

The corners of the stamped steel case ground the tach. Every A-body plastic gauge housing (dash bezel) has some sort of metal ground straps attached to it, has to have this. On '66's there is a mean little sharp bracket that grounds off the steering column attachment area, its a ground for the cluster hsg. Years ago, i carved up my right index finger good on one those. '65, though it as a smaller bezel, has to have something similar.

Tach feed wire. This wire was brown has an inline clear or opaque fuse holder in it. These are reproduced. Under the hood, the tach wire attaches to the negative terminal on the coil, eventually goes back to a rubber grommet in the cowl, then winds through to the S terminal on the back of the factory tach. Original fuse holder in this wire often was yellowing out with age on an original tach feed wire. In the 80's, I used to watch for this feed wire & the factory grommet in project cars that had prev had the gauges yanked out, let me know car originally had rally guages. 1 amp glass fuse is used in the holder.

Last, if your car was equipped with a factory clock, it will have a pigtail for the bulb sockets. Believe the wiring is gray(?) If not, believe this little wire harness is a jumper & is avail from M & H or American Autowire. Have fun!


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## Roqetman (Aug 31, 2015)

Ok, thanks for the info. This sounds more expensive than what I expected since I've to have it converted for HEI. The price for the used tach and then converting it is not worth it to me. I have a S-W tach mounted in the dash to the left of the clock and it works fine. I like the old hot rodders mentality... use what you got! LOL!


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