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While working on my 56 F-100 Panel I noticed that the sending unit looked a lot like the sending unit on my retro fit GMC G-20 fuel tank in my 56 F-100 truck. I pulled the trucks sending unit and pickup out and aside from the sending units color being different they seem to be interchangeable. I tried to find info on the sending units and found that in some places they are called fuel cards but I couldn’t find a source for them. Any suggestions on sources for the sending unit portion of the fuel pickup and sending unit assemblies?
The reason this would be of interest is the GMC unit (0-90) is different OHMS than the older Fords (10-73). If I can find a source for the Ford fuel card I could change the GMC unit and avoid having to install a sending unit converter between the GMC sender and Ford bi-metal Gauge.
Have you taken any of these old sending units apart on these old trucks? The reason I ask, I had a 1953 F100 with the 6v + ground system. I took the original sending unit apart, it did not work on the variable resistor method at all. It was like a turnsignal flasher inside. The sending unit constantly grounded and ungrounded the wire from the dash gauge. The sending unit arm mechanically pushed on the "flasher unit" inside the sending unit, which changed the duty cycle of the flashing. This made the gauge read higher or lower. It is very much related to the cluster voltage regulators that Ford used for years all the way up to 1986. They also sent a flashing voltage to the cluster, and automatically changed the duty cycle of the flashing to keep the gauges reading constant as the voltage from the vehicle varied.
Maybe they changed this around in 56 when they went to 12v?
I guess I forgot to add my panel had a aftermarket sender in it. This is what the two senders look like. Again I’m not looking for the complete pickup & sending unit, just the sending “card”.
Complete GMC pickup & sending unit GMC “card” 1st side Replacement Ford “card” 1st side GMC “card” sweep arm side Replacement Ford “card” sweep arm side
