# Tachometer help



## Destro23 (Aug 4, 2016)

I have a 1968 LeMans Convertable (GTO clone/tribute car) the previous owner had electrical issues and literally starting pulling and cutting wires to "figure it out" because anything you touched that had to do with electricity it would shut off... he thought it needed to be rewired. I had a mechanic trouble shoot it 5 years ago when i got the car and it was just the voltage regulator needed to be updated. 

So fast forward to today and I want to get my dash back up and and running. The speedometer was unplugged so i plugged that in today and it works!!!! only a few mph off(iPhone tracked speed). But the RPM is not working... behind the dash a brown wire that slides onto the tab. I plugged that back onto it but i'm not sure where exactly on/around the coil it should be plugged into... can someone post a pic of what I should be looking for? I do have a laminated wiring diagram that i can reference as well. and i'm going to be posting about


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## O52 (Jan 27, 2019)

If you have a factory tach there should be a brown wire with a fuse holder attached to the negative terminal of the coil. (Points distributor) Check for an open fuse . 























Laminated drawings do not show the tach wiring or any of the other minor options. 
For the price of the laminated drawing you can pick up a used service manual which will show everything, or pay a
little more for a new reprint.









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## Destro23 (Aug 4, 2016)

Perfect! I'll check tomorrow after this storm blows through! exactly what I needed... the brown wire on the tach was pulled off but not working... now I know what to look for.

Thanks again! I'll pick up that book becasue there is a few things cut and a few things unplugged I'll be posting that soon. hopefully I can get power back to the radio eventually after I have cluster figured out..


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## Destro23 (Aug 4, 2016)

Ordered the manual! and may have found the issue. many more to come.. brown wire is disconnected under the hood and just hanging there next to a green wire that is cut and just hanging there.

behind the tach there are 3 wires that are unplugged (previous owner troubleshooting) 
1. Brown (tach) yes i've plugged it in
2. Light Grey - dash lights? the grey light wires on the tach are snipped (prob more of his troubleshooting)
3. Orange/Blk Stripe ? I forgot my color wiring poster at home so haven't mapped it yet.


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## O52 (Jan 27, 2019)

Brown wire - Tach Terminal
Grey wire -Dash Lights, find the pigtail from the tachometer lights and plug it in to this. If the pigtail is cut you can splice the wires together or find the correct type of terminal to make repairs. You can order a new pigtail for the tach lights.
Orange/Black Tracer- 12 volt Battery Wire. Used for accessories such as the clock, remote trunk release, courtesy lights. If you have none of these just leave it open.

The brown(Tan) wire by the frame is for the brake distribution valve switch. Lights up the brake light if you have a fluid leak. Should have a pin terminal to plug into. 
Green wire goes to the horn relay above the master cylinder. Activates your horns

The tach may or may not work with an electronic distributor. It is designed for a points distributor.


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## Destro23 (Aug 4, 2016)

awesome thanks... from what i've been reading if i switch over to an MSD system there is a conversion module that will make the Tach work again. Doing research on that now


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