Classic/Antique Car Repair: 69 Mustang fuel guage, fuel gauge, tank unit

Question
I took the dash off to repair a rusty lower cowl. After the repair I installed new printed circuit and led lights in dash. I have bolted up the dash and the fuel gauge is not working. The fuel tank is new and it is connected. Is there a ground that I missed? The oil and temp are run to a pod on the console.

Answer
The fuel gage is grounded by the fuel gage tank unit. Time to get a voltmeter and make sure that there is voltage getting to the fuel gage dash unit. There is a device on the back of the dash called a constant voltage regulator that sends a constant 5 or so volts to the gas gage. Check and make sure that is connected and is getting full battery voltage when the key is on.
Brad