Fuel Tank Selector Valve Wiring

[Don Quixote]

For those wanting to use an regular on/off switch to switch fuel tanks, I researched wiring and found nothing so I created my own. I attached my wiring diagram and my push/pull switch. I hope this helps somebody as it was rather painful to put it all together.

[jocko]

Nice job Don. I'm assuming you're running two saddle tanks and no interior tank, is that right? And the push/pull switch is the one just below the choke pull? Looks like a nice clean job and thanks for sharing. If you eliminated the cab tank, then the wiring should be similar to a factory NL2 aux tank wiring arrangement. Wish I'd known you couldn't find the wiring diagrams you were looking for - I know it's too late, but here's some I have had saved away - some are for saddle tank arrangements, some for NL2, they may or may not have been any help to you - and may or may not be of any help to anyone else, but this is potentially a great ref thread, so will add to the pile of refs. Thanks again for posting, very helpful and I like your stealth switch arrangement. Any details on how you did that? it looks great.

1st 2 pics are for dual saddles and the last 2 pics are factory NL2.

[RichardJ]

Jocko, that just switches the gauge to L/R tank sensor. That's used with manually switched tank fuel lines.

The switch for the later tank Selector valve is much simpler and requires no relays and is actually more user friendly.
Flipping the toggle up or down, allows you to check fuel level in the other tank without actually changing tank feed. Pressing on the toggle , in either the up/down position then changes the tank.

I'm not sure what your switch is doing, but it may be energizing the selector solenoid at all times and it shouldn't. It only needs power when switching.

And, the correct switch is only $14 at O'Reilly, BWD Part # S743.

[Don Quixote]

Originally Posted by jocko

Nice job Don. I'm assuming you're running two saddle tanks and no interior tank, is that right? And the push/pull switch is the one just below the choke pull? Looks like a nice clean job and thanks for sharing. If you eliminated the cab tank, then the wiring should be similar to a factory NL2 aux tank wiring arrangement. Wish I'd known you couldn't find the wiring diagrams you were looking for - I know it's too late, but here's some I have had saved away - some are for saddle tank arrangements, some for NL2, they may or may not have been any help to you - and may or may not be of any help to anyone else, but this is potentially a great ref thread, so will add to the pile of refs. Thanks again for posting, very helpful and I like your stealth switch arrangement. Any details on how you did that? it looks great.

1st 2 pics are for dual saddles and the last 2 pics are factory NL2.

I appreciate that. It was a lot of work to figure out the diagram. You should have seen my face when I finished and it all worked.

I'm running the in cab tank and a Blazer tank in the back. I got the push pull switch from the parts house and replaced the button with a choke knob. The 2 power wires run to behind the seat and I used a 4 pin trailer connector to run them under the truck through the floor as well as the wire for the in cab fuel tank gauge. I am also running a single mechanical fuel pump.

[Don Quixote]

Originally Posted by RichardJ

Jocko, that just switches the gauge to L/R tank sensor. That's used with manually switched tank fuel lines.

The switch for the later tank Selector valve is much simpler and requires no relays and is actually more user friendly.
Flipping the toggle up or down, allows you to check fuel level in the other tank without actually changing tank feed. Pressing on the toggle , in either the up/down position then changes the tank.

I'm not sure what your switch is doing, but it may be energizing the selector solenoid at all times and it shouldn't. It only needs power when switching.

And, the correct switch is only $14 at O'Reilly, BWD Part # S743.

It is a constant on but the switches for the later years were not momentary either so that's how I knew it would work. My intention here was to not install a switch that didn't belong in the truck and this one looks like it belongs. I didn't have to drill the dash either. If someone has any idea how to make it easier than an on/off switch, I'm open to suggestions.

[Don Quixote]

Originally Posted by RichardJ

Jocko, that just switches the gauge to L/R tank sensor. That's used with manually switched tank fuel lines.

The switch for the later tank Selector valve is much simpler and requires no relays and is actually more user friendly.
Flipping the toggle up or down, allows you to check fuel level in the other tank without actually changing tank feed. Pressing on the toggle , in either the up/down position then changes the tank.

I'm not sure what your switch is doing, but it may be energizing the selector solenoid at all times and it shouldn't. It only needs power when switching.

And, the correct switch is only $14 at O'Reilly, BWD Part # S743.

I should add the one switch switches the tanks and the gauges.

[jocko]

Originally Posted by RichardJ

Jocko, that just switches the gauge to L/R tank sensor. That's used with manually switched tank fuel lines.

That's correct Richard - just switches what is being reported on the fuel gauge.

EDIT: Thanks for pointing this out Richard - I kinda missed the mark on my post, it's not exactly pertinent to the thread and what the OP has accomplished or what you're talking about. Just to be crystal clear for folks that read this down the road, post #2 is for wiring a selector switch (either the factory switch for RPO NL2 or aftermarket saddles) to choose which tank is displayed on the fuel gauge only, totally independent of manually switching the fuel source tank (on the floor board). Sorry for injecting confusion.
I kinda prefer the manual setup as it allows me to check tank qtys without switching. But power switching the fuel source would be kinda neat too

[RichardJ]

>>but the switches for the later years were not momentary either <<
What later years? Parts reference lists this switch as used up to 1991.
Leaving that solenoid constantly powered and heating up is a bad idea.

Your switch, relays and extra jumble of wire didn't belong on the 67-72 truck either.

[Don Quixote]

If all it did was switch the sending units, I'd think it was an awful lot of work for something I could have done with a toggle switch under the dash. I also don't think I would have made a pretty picture of my wiring schematic either.

[Don Quixote]

I'm sorry, I had no intention of offending anyone with my work to my truck. My intent was to show work I did to it that works. I had no idea it was going to be chewed up with base assumptions from folks who didn't bother to read my post to begin with.

The stock non-momentary switch was found on models with TBI. This was necessary as the fuel pumps got their power off the valve's power supply and fuel pumps need to run something along the lines of not momentary.

For the record, I do not require anyone's permission to add, change or delete a damn thing on my truck.

[harpo231]

Originally Posted by Don Quixote

I'm sorry, I had no intention of offending anyone with my work to my truck. My intent was to show work I did to it that works. I had no idea it was going to be chewed up with base assumptions from folks who didn't bother to read my post to begin with.

The stock non-momentary switch was found on models with TBI. This was necessary as the fuel pumps got their power off the valve's power supply and fuel pumps need to run something along the lines of not momentary.

For the record, I do not require anyone's permission to add, change or delete a damn thing on my truck.

Amen to that !