In the figure below you can see how I mocked up the system to test the sender/fuel gauge setup. The sender has two terminals: ground and signal. The signal lead goes to the signal input on the Fuel Link. The Fuel Link output goes to the fuel gauge. The Fuel Link requires 12v and a ground. The fuel gauge needs the signal input from the Fuel Link and a ground. I used my DC power source to simulate the battery. The power source can only supply a maximum of 5 amps but the gauge and Fuel Link together draw only about 0.13 amps.
The actual calibration is easy. A calibration button on the Fuel Link is pressed and then the 12v power is switched on. Once the power is on, I could toggle between the preset sender translation settings until I landed on the one for the Ford sender. After that selection, the programming sequence provided a means, via the calibration button, to define when the fuel gauge was empty, full or at intermediate steps in between.
After I was satisfied that the system was working as expected, I took the test configuration apart and re-assembled it on the car using the wiring from the wiring harness (photo below).
The Classic Instruments gauges have a seperate 12v input for the gauge lighting and I tested that in the mockup.
I discovered one quirk (actually my error) in the gauge lighting system. I have partial sweep and full sweep gauges. The partial sweep gauges, like the fuel level gauge, only require the gauge light power for the gauge lighting to work. The full sweep gauges (oil T, oil P and water T) in addition require gauge power for the lighting to operate. I didn’t realize that, even after reading the instructions, and suddenly thought that the gauge lighting on the full sweep gauges was faulty. I called Classic Instruments and was told that I needed gauge power, too. I felt pretty dumb but the tech guy told me that lots of people have the same issue (or maybe he was just trying to make me feel less dumb!). Anyway, once I added the gauge power all worked well.
Finally, I set to work organizing the input leads to all of the gauges. Gauge power and gauge lighting power were daisy-chained from the wire harness power leads. All of the grounds go to grounding busses that are connected to a grounding loop that I have running throughout the chassis.
Just as I was getting my momentum up on the wiring it was time to head back to MN. I’ll be here for roughly 6 weeks and then head back to UT and continue on the path to getting the wiring done. Once I figured out a few key principles, the wiring is not that daunting. Now, it’s primarily an issue of being organized and tidy. To the extent that I can, I’m testing each sub-system so that if a problem arises, I’ll be able to isolate the cause relatively easily. In this regard, two items are, in my opinion, absolutely necessary for doing electrical work: 1) a DC power source (not the battery) and 2) a conductivity tester, preferably with a DVM.