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I drew up a schematic of the 1968 GTO/Lemans/Tempest circuit board using an actual repop circuit board. These are said to fit 1968-1972, but cannot confirm that as sometimes there are changes within the years. This is for my '68 Lemans. It is the non-rally gauge circuit board having the idiot lights.

I wanted to show both the Ground (G) and Power (+) sides of the lighting used to illuminate the dash and the idiot lights. I also show the various Grounds Screws that secure the circuit board to the metal dash pod. My car has the Speed Warning Speedometer and uses a brass contact pin seen in the upper right, otherwise that hole will be blank. My fuel gauge also has the low warning light as part of the Speed Warning option, so my hook-ups may look a little different from the standard fuel gauge. Red/Green are ground wires while the Black wire is a power/stud to the gauge. There is 1 small hole above the Oil Light socket which I do not know what it is for.

The wiring harness dash plug gets fitted into the Harness Plug position, and has copper "fingers" that make contact with the corresponding Harness Plug connections, 5 on top & 6 on bottom. I included a contact diagram in the lower left outlining what each "finger" powers on the circuit board. NOTE: Do Not apply 12-Volt power to the ground fingers in an attempt to diagnose/trouble shoot a bad electrical connection. You WILL melt/damage the circuit board copper circuitry as both the circuit board plastic and copper circuitry are very thin and if shorted out, ie applying power at the ground "fingers," will produce the smell of melting plastic and heat where it has melted. This will require that you spend another $100.00 plus shipping to replace the melted circuit board - just sayin' :oops:

Also included a pic of the back of my dash/cluster pod so you can see how it lays on the back and the light sockets are positioned.

1968 GTO -Lemans Circuit Board.JPG
1968 Cicuit Board pic.JPG
 

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I drew up a schematic of the 1968 GTO/Lemans/Tempest circuit board using an actual repop circuit board. These are said to fit 1968-1972, but cannot confirm that as sometimes there are changes within the years. This is for my '68 Lemans. It is the non-rally gauge circuit board having the idiot lights.

I wanted to show both the Ground (G) and Power (+) sides of the lighting used to illuminate the dash and the idiot lights. I also show the various Grounds Screws that secure the circuit board to the metal dash pod. My car has the Speed Warning Speedometer and uses a brass contact pin seen in the upper right, otherwise that hole will be blank. My fuel gauge also has the low warning light as part of the Speed Warning option, so my hook-ups may look a little different from the standard fuel gauge. Red/Green are ground wires while the Black wire is a power/stud to the gauge. There is 1 small hole above the Oil Light socket which I do not know what it is for.

The wiring harness dash plug gets fitted into the Harness Plug position, and has copper "fingers" that make contact with the corresponding Harness Plug connections, 5 on top & 6 on bottom. I included a contact diagram in the lower left outlining what each "finger" powers on the circuit board. NOTE: Do Not apply 12-Volt power to the ground fingers in an attempt to diagnose/trouble shoot a bad electrical connection. You WILL melt/damage the circuit board copper circuitry as both the circuit board plastic and copper circuitry are very thin and if shorted out, ie applying power at the ground "fingers," will produce the smell of melting plastic and heat where it has melted. This will require that you spend another $100.00 plus shipping to replace the melted circuit board - just sayin' :oops:

Also included a pic of the back of my dash/cluster pod so you can see how it lays on the back and the light sockets are positioned.

View attachment 140747 View attachment 140748
another great resource Jim, Thank you for sharing.
I drew up a schematic of the 1968 GTO/Lemans/Tempest circuit board using an actual repop circuit board. These are said to fit 1968-1972, but cannot confirm that as sometimes there are changes within the years. This is for my '68 Lemans. It is the non-rally gauge circuit board having the idiot lights.

I wanted to show both the Ground (G) and Power (+) sides of the lighting used to illuminate the dash and the idiot lights. I also show the various Grounds Screws that secure the circuit board to the metal dash pod. My car has the Speed Warning Speedometer and uses a brass contact pin seen in the upper right, otherwise that hole will be blank. My fuel gauge also has the low warning light as part of the Speed Warning option, so my hook-ups may look a little different from the standard fuel gauge. Red/Green are ground wires while the Black wire is a power/stud to the gauge. There is 1 small hole above the Oil Light socket which I do not know what it is for.

The wiring harness dash plug gets fitted into the Harness Plug position, and has copper "fingers" that make contact with the corresponding Harness Plug connections, 5 on top & 6 on bottom. I included a contact diagram in the lower left outlining what each "finger" powers on the circuit board. NOTE: Do Not apply 12-Volt power to the ground fingers in an attempt to diagnose/trouble shoot a bad electrical connection. You WILL melt/damage the circuit board copper circuitry as both the circuit board plastic and copper circuitry are very thin and if shorted out, ie applying power at the ground "fingers," will produce the smell of melting plastic and heat where it has melted. This will require that you spend another $100.00 plus shipping to replace the melted circuit board - just sayin' :oops:

Also included a pic of the back of my dash/cluster pod so you can see how it lays on the back and the light sockets are positioned.

View attachment 140747 View attachment 140748
Jim where does the light that powers the ash tray light plug into? Mine fell and I can鈥檛 tell where it fell from
 

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Discussion Starter · #5 ·
Jim where does the light that powers the ash tray light plug into? Mine fell and I can鈥檛 tell where it fell from
Read this post, it may answer your question.

 
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