I'm rebuilding my 59 f250 and I'm ditching the stock in-cab tank.

My buddy gave me his dual tank setup at of his 80's cheby parts truck. The tanks each have their own sending unit and I have the solenoid valve and dash switch.
I want to rig it up so the gas gauge reads only from the tank the switch is set to.

Is my stock gauge compatible with the stock cheby sending units?

It would make sense to me that all sending units would simply read between 0 and 100% resistance and all gauges would be resistance meter. This making all sending units work with any gas gauge. However I had someone tell me that many are not compatible.
Can someone explain?

 

I did somewhat the same thing years ago with a model 'A' sedan using saddle tanks mounted under the running boards. There was a three position toggle switch which controlled which tank you were using and reading. I had it wired so that in the left position the left tank was being used and the fuel gauge showed the fuel level in that tank. In the right position it read and used the right tank. The middle position was off.

The problem you will have is that your Ford gauge is not going to read the fuel level in either tank properly. Chevys of the 80s used sending units with a resistance of zero ohms empty and 90 full. Your 59 gauge will be looking for 10 empty and 73 full. If the tanks in the parts truck are aftermarket then they might have the common aftermarket 33-240 range senders and an aftermarket gauge matching that resistance would be necessary. Either way you will have to either match the senders in the tanks with a new gauge or buy new senders and a matching gauge.

 

Bit of a record, this item hasn’t come up for more then a month.

Something else to keep in mind, the early switches has three wires for the gauge, hot, left, right but the switch has only two for the fuel solenoid, one hot and one for tank selection as the tank is selected by a electrical activated spring loaded valve. With no power it always switches back to the same tank because of the spring. These where a one wire solenoid.

gas gauge info.jpg

 

Well, I't definately a record - almost a month, Old F1 - almost as long as "my signals aren't working correctly". Seem like we need to write a "tech" about this and post it. I guess Adrian is working on that kind of thing.

This has a lot of "Apples and Oranges" in it. I had a dual tank set up in my 55. I had the stock running board tank then installed a 56 tank behind the seat. That was really nice because at the time I was commuting long distances between work and family on weekends. Difference was 6 and 12 volt senders and a 6 volt gauge. I ended up putting in a 55 sending unit on the 56 tank.

I could probably go into a long electrical theory dissertation, but to spare you I'll just cut to the chase.

You aren't going to be able to use the Chevy gauge. It's electrically compatable with the sending units, but it was installed and fed in it's original vehicle via a printed curcuit and will be almost impossible to physically mount and connect in your set up.

Here is what I suggest. Take the sending unit out of your existing tank and buy a second one. Modify the float arm lengths to fit the new tanks, and make adaptor rings to mount them to the new tanks. It shouldn't be too difficult. The arm length is just cut to shorten or an extension put in and solderer together. And the adaptor rings are just a round plate with holes drilled in the right places to mount the new sender and bolt the ring to the tank - cut a cork gasket.

Lastly, there used to be a gas tank selector valve in many of the "Camper Specials" and motor homes with dual tank set ups that would select one tank or the other to draw gas from and at the same time electrically switch the input from that tanks sending unit - so the gauge reads correctly from the tank being drawn on. These should still be available at a trailer supply or motor home store.