I've been working on a solution for my 1986 F250 with a 460. I recently replaced the tank with a new one and a new fuel pump assembly. However I had to use the sending unit for a 1987 since the 1986 one is no longer available , at least not readily.

My plan is to install an Autometer 2518 Gauge for measuring the level in the rear tank only since the range of the transmitter is different from the stock one.

Just as a FYI:

1986 F250 Range: 73 ohm empty, 10 Ohm full

1987 F250 Range: 16 Ohm Empty, 158 Ohm Full

I have the location to tap into the connection for the rear tank sending unit, now I need some suggestions where to pull power and ground near the steering column. I need a line that goes on and off with the ignition and I need to fuse it with a 4 amp inline fuse which I have.

I have checked the connection for the rear tank with a multimeter and I'm getting the expected reading of around 158 ohms with a full tank which is correct (it's actually 159.4).

Any pictures and wiring diagrams would be appreciated.

So far the help here has been phenominal and I appreciate everyone's input. I plan to take pictures of this whole process this time and writeup an explanation of what I do.

 

Red/yellow-hash is key-on power, it feeds various solenoids under the hood. If you have one of the black boxes, there will be one of those wires down near the gas pedal attached to a black box about the size of a pack of cigarettes with wires going through the firewall.

For ground, I dunno, find a good place for a ground wire.