[wilmer496]

Guys,
I am installing one of these aftermarket Rally gauge kits into my -67 Tempest. My orig wiring is all gone so i have made my own but as i am also lacking all sockets, i have no idea of what goes where on the fuel gauge.

As per my research here, i believe it should be as in my pic?
+ = Power
S = Sender

Can anyone confirm this?

Thanks!

[Old Goat 67]

I'm pretty sure you are correct, Dark brown wire is hot, Light brown wire goes to the sender.



Full schematic.



Charles

["QUICK-SILVER"]

That does look correct and matches a 70 firebird guage I've got laying here.

You can check the terminals with an ohm meter to be sure.

Ohm test each terminal to ground. The one with the highest ohm reading will be power supply. That leaves the lower ohm reading terminal as sending unit.

A 68 bonniville gauge I checked had 100 ohms between the sending unit terminal and ground. 45 ohms between the two terminals. And 145 ohms between the (+) terminal and ground.

Clay

[wilmer496]

Boys, thanks a lot for the fast reply!

I am fairly good at electrics but that comment on checking ohm ratings was clever, you learn every day!

[Peter Serio]

One other thing I would do here would be to make yourself a extra ground wire that attaches to the lonesome threaded stud as shown by the blue arrow.

Connect it to a place under the dash, (hidden) metal where you can sand off a clean spot to attach a ring terminal to the end of your wire with a small star washer and a self-tapping sheet metal screw-bolt.

in 1966 and 1967 on the lemans GTO bodystyle there is NO factory ground wire for that cluster. It only had ground via overlapping pieces of sheet metal (when the car was brand new and fully assembled) with the original non-rally gauges. The factory (grounds) those thin metal pieces are often, after all these years rusted, missing and/or corroded.

Missing ground on gauges is VERY common and; often overlooked problem which you will damage your new gauges in about 2 minutes if you power those up via your key switch; without a solid ground at the gauge cluster!!!!
NOTE: This includes BOTH parts of that reproduction dash. The main housing, where your fuel gauge, speedometer and tachometer rests as well as the separate (4th) pod that has your water (coolant) temperature and oil pressure gauges in it!!!

[wilmer496]

Good advice, Peter!

I have all the metal pieces for ground and i have also added a separate ground wire from the housings to car body.

I do have full continuity from each housing to the gauge pins you mentioned but i will add ground wires as you suggested. Won't hurt!

Thanks!

[Peter Serio]

Here is a drawing from a 1964 manual that shows where GM attached the ground wire for the A body dash cluster.

NOTE: (This location was used for the factory black wire for both 1964 and 1965, Tempest, Lemans & GTO.)