# 1968 hood tach



## 1968GTOMAN (Aug 3, 2020)

Hi, my present hood tach is missing bulb sockets and wires missing so i bought a new one from Original Parts.
This one has a 3 prong plug. Theres no wire in engine with that plug recepticle. I admittedly dont know how to hook it up. On the distributor there is a tab labeled "Tach" so i know a lead goes there, nothing hooked to it now. 
I have a points distributor, but oddly cant find the coil. There has to be one right?
Ive searched, cant find it.
Thanks!


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## BLK69JUDGE (Jun 10, 2010)

Welcome 
so your workin on a 68 eh ?



> > On the distributor there is a tab labeled "Tach" so i know a lead goes there, nothing hooked to it now. <<


hmmm " I do believe " you DONT have points and that is an HEI distributor

pictures always help if you can post them

is that a picture of your new tach ?

there is a totally separate harness for the hood tach 

Scott


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## O52 (Jan 27, 2019)

Like Scott said; you need a separate harness that connects to the coil, lighting and ground. 

From OPGI Catalog
wiring-harness-tachometer-1968-gtolemanstempestskylark-hood-mounted-mh12375.html

The tach may or may not work with the HEI distributor. Plug the coil lead to the Tach terminal and check for operation. You may need a filter if the reading is inaccurate.


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## 1968GTOMAN (Aug 3, 2020)

Thank you very much!
Yes i just learned it has an HEI.
A filter you say?

Thanks, im researching this.


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## 1968GTOMAN (Aug 3, 2020)

I just called MSD co. They of course sell ignition stuff, they said that most likely my tach will work with the HEI, but if it doesnt and "Picks up noise", I could use a 10 KO 1/2 watt resistor in line from distributor.
I found in the box under some packing material the Harness!! Sucks I just ordered one.
Should be simple at this point youd think...?
The fused lead, which has the pin stripe, says goes to coil, so for this HEI system, i guess cut that wire and put a female wire connector to attach to the distributor where its marked "tach." And then the red plastic connector goes to the lights i assume?
If anybody has any more input or can stop me from doing anything dumb Im very much appreciative! And thank you for your previous replies!
Bill


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## O52 (Jan 27, 2019)

There should be a rubber grommet to the right of the master cylinder. Feed the grey wire with the red connector through the grommet. It snaps out so you can thread the wire through the slit without pushing the plug through. Run the grey wire over the speedometer and you should see a grey wire with a connector just behind the clock/blank plate to the right of the speedometer. Just like the drawing.


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## 1968GTOMAN (Aug 3, 2020)

Thank you!
I guess that wont have the dimmer capability? Be nice it i could could control that with the cluster lights brighter or dimmer. I saw somewhere theres a kit that has to be added for that.
But if theres a prewired connector i guess its possible it will dim.
I really appreciate you guys help.
This is great! 
My car is in shop to figure out a ticking noise in the upper engine so i have to wait until i can get it home.
Thank you, ill let you know how tach turns out. Its gonna be badass. Its a beautiful car. The 68 GTO is arguably the most iconic car on the planet. Ive only owned it about 50 days. Pic attached.


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## O52 (Jan 27, 2019)

It should dim when connected to the grey wire.


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