The tank switch, was it all electric in '74 or electric switch for gadge and manual with a valve? I have the latter

 

The tank switch on a '74 only read the signal from the sending unit in the tank
to tell you the fuel level , actually I think it only read the ground wires of each .

The tanks were switched wit a valve which you turned manually and the engine fuel pump simply pumped from the other tank .

 

i thought that i had seen the electric wiring for the switching solenoid on the frame of my '73, but maybe not. i will have to look and see what is hanging there

 

Thats what it is so(now)......that is what it was(in '74).....and thats what it will be. Oh thats what it looks like.

 

i wish someone with some knowledge could look at this thread and let us know if these valves were aftermarket throw ins when the frame solenoid went, or if the switch is purely for the guages

 

Hi-Boy brand spanking new with aux tank, it came with a single double-pole switch that was mounted under the dash and to the left of the steering wheel. That switch controlled both the tank signal and activated a solenoid valve when "hot" to connect the aux tank. I suppose it's possible that the 4x4's got different treatment than the 2xs, but would be surprised.
I have since upgraded to the switch incorporated into the later model heater controls module, and it connected the same way.
JFWIW. Steve

 

maybe it was dealer installed?