Electrical: GT Hawk dash grounding

[ColoradoHawk]

I just finished redoing the dash on my 63 Hawk by putting in cherry wood veneer. Now my temp gauge only goes up to about 140 as soon as the car is started and will go no higher. Also, my gas gauge goes immediately to full. In researching the problem, I believe it's because of a bad ground. How exactly is the dash on a 63 Hawk grounded?

[Jeffry Cassel]

The ground is a black wire that goes from one gage or pair to another and to ground. Take your VOM and see if you have each gage grounded; chances are something was missed in reassembly. You can always run another ground, too.

[bezhawk]

Actually it's red/white tracer stripe.

https://www.studebakerparts.com/studebakerparts/store/s/html/images/63-4-hawk-wire.jpg

[JoeHall]

Its been awhile, but I believe the copper oil pressure line provides ground, at least for the fuel gauge. But I seem to recall a ground wire then runs from the fuel gauge to the heat gauge, to ground that gauge also. Since that is a common for both those gauges, I'd make sure the oil pressure line clamp, on the engine bay side of the firewall is secure; it also must make a good connection with the copper pressure line.

[ColoradoHawk]

I'm not very knowledgeable at all regarding most things electrical. I've decided that running another grounding wire will be the easiest solution. Now my question, which terminals on the gas gauge and temp gauge do I connect the ground wire to? I'm really nervous about connecting something wrong and causing damage or fire. Thanks guys!

[bezhawk]

There should be four terminals on both the gas, and temperature gauge. Two of the studs pass through the light box through insulated plastic spacers. They are the power and sending unit terminals. the other two will just have the 3/8" nuts holding the gauge into the box, those you can ground.

[JoeHall]

If your cigarette does not work, you might wanna ground it to the same place. The gas gauge, temp gauge and cigarette lighter all share a common ground, near as I can tell in the Shop Manual.

[Dan Timberlake]

If your cigarette does not work, you might wanna ground it to the same place. The gas gauge, temp gauge and cigarette lighter all share a common ground, near as I can tell in the Shop Manual.

That looks correct but only for the individual instrument lights, as marked in Blue. The signal for the gas gage and temp gage "grounds" thru the sender in the tank and in the block respectively, as I marked in orange and brown. The variable nature of the resistance in the senders is what changes the gages' displayed readings.

The power from a bunch of things comes from one of the fuses in the fuse block.

[bezhawk]

The ground for the lights IS through the case of the instrument. That is electrically isolated from the gauge operation.

[ColoradoHawk]

My temp gauge is now pegged at full hot. Won't go down even after turning the ignition off. I have the orange wire on the bottom (6 o'clock) and the white with black tracer at the top (12 o'clock) should I reverse the wires?

[JoeHall]

My temp gauge is now pegged at full hot. Won't go down even after turning the ignition off. I have the orange wire on the bottom (6 o'clock) and the white with black tracer at the top (12 o'clock) should I reverse the wires?

You may have fried the gauge already, but I'd start by disconnecting the wire from the sender. Then, with key off for at least 1 minute, tap on the gauge face with your fingertips. It may drop back to Empty. If that happens, there's possibly a problem with the sender circuit, or the wires are hooked up wrong at the gauge.



Update: I just went out and looked at the wiring on my 63GT's gas gauge. The red & black wire is on top, white & black on bottom, and ground on the left side mount bolt, as sitting in driver' seat. I may have installed that ground wire at some point, but the gauge works perfectly.

[ColoradoHawk]

You don't have an orange wire? That's the wire that goes to the temperature sender in the cylinder head.

[JoeHall]

You don't have an orange wire? That's the wire that goes to the temperature sender in the cylinder head.

Oops, I was looking at the gas gauge. On the temp gauge, top is orange, and bottom is white or white & black, hard to see for sure. Top wire is definitely orange though.

[ColoradoHawk]

A million thanks JoeHall!!! I know what a PITA it is to look under a Hawks dash.

[Paul Keller]

This may be over-doing it, but... grounds are a regular problem w/ older cars, especially when the dash (or entire body) is made of fiberglass. On my '63 hawk I ran a 16 Gage wire from the mounting stud on the clock, through to the right side Tach, thereby connecting all together. Also, a wire has been run from each side (left & right( to a place on the firewall (providing a ground to the body). The same point on the body is connected to the frame (as a ground) and, separately, to the engine - Tying all together as a common ground.

Paul TK