Manual Fuel valves with stock gauge

[clayhwalker]

I have a 1988 F350 that I have installed manual fuel/return valves on but I believe the the stock selector valve electronics have finally completely craped out and that is how I was making my fuel gauge work with the stock selector switch.
Is there a cost effective way to make my stock gauge work when I use the original switch without buying a new fuel switch valve. I only need the electronics since I have Manuel valves to swap fuel supply.

 

[Rocknit4x4]

I don’t have the TSV wiring diagram handy but I would think a standard 12v / 5 pin relay could be used in place of the TSV for just the signal to the gauge.

 

[clayhwalker]

Would that allow me to still use the factory switch on the dash so I would have proper fuel level indication on my gauge?

 

[IDIBOBS]

This is exactly why I always put things back to factory. Dump the manual valve and put in a proper valve again. If it was ok for ford 30plus years ago it’s ok now. No head ache it’s just maintenance. Too many band aids that end up more work than just doing it right in the first place.

 

[chickenpot]

Hey!

I have a 1988 F350 that I have installed manual fuel/return valves on but I believe the the stock selector valve electronics have finally completely craped out and that is how I was making my fuel gauge work with the stock selector switch.
Is there a cost effective way to make my stock gauge work when I use the original switch without buying a new fuel switch valve. I only need the electronics since I have Manuel valves to swap fuel supply.

Hey! ive been trying to figure out the same thing on my 93. Wonder if the circuits are the same between brick and aero.. Im using some heavy duty hydraulic spool valves as selector valves because the stock selector is weak for my setup. Ive been chasing an issue where both tank sending units ohm out perfectly from full to empty but the dash gauge constantly reads high, leading me to believe that the signal to the dash is meeting resistance somewhere causing higher readings, and my suspicion is it's somehow through the selector valve or it's wiring harness. valve is still there plugged into power but no fuel going through it. Ive tried looking at the diagram but not sure if i can make it work that the dash switch just switches between the sending units and nothing to do with the selector valve

 

[clayhwalker]

Well I just tore my whole cluster out and it looks like my issue is the cluster circuit board. It’s fallen apart in several places when I start wiggling things around my gauge starts working. If anyone knows where I can buy one I can’t seem to find the right one on eBay.

 

[Jesus Freak]

I have a manual valve myself and my returns are plumbed to my rear tank, because I run WMO. It took a bit, but I unplugged the plug on the stock valve and through process of elimination figured out what to jumper so that my rear tank would read. I wasn't worried about the front tank, because it's my clean diesel tank. Sometimes it would be convenient to know what's in the front tank, but my rear tank is the important one (it's a 30 gallon bronco tank). I'm sure if I was really concerned I could get under there and figure out how to have them both jumpered. But really, good call on dumping the electric fuel selector, they basically suck......air that is.

 

[franklin2]

The original valve besides switching the plumbing for the fuel, does have the chore of electrically switching the sending units also.

Several ways to eliminate this and switch the sending units another way;

1. Use the dash switch and a relay under the truck like was already mentioned. This will put the relay in harms way under the truck with all the dirt, salt and water under there, unless you could mount it in a box.

2. Wire another switch for this circuit and just forget the dash switch. If you have your manual valves say, behind the driver's seat in the floorboard, you could mount a electrical switch to switch the sending units also. You could put it inside the cab in a safer place, and the wiring would not be that far away from the original location of the valve.

Looking at the above, I suppose you could add a relay and mount it inside the cab near the rear floor area and still use the dash switch.

The original valve had a little motor in it. The dash switch is more like a power window switch. It is wired to switch the polarity of the voltage going to the valve motor, making it switch direction to switch tanks. So there is only two wires going from the dash switch to the valve, that is not much help in switching the sending units unless you use a relay.

 

[chickenpot]

The original valve besides switching the plumbing for the fuel, does have the chore of electrically switching the sending units also.

Several ways to eliminate this and switch the sending units another way;

1. Use the dash switch and a relay under the truck like was already mentioned. This will put the relay in harms way under the truck with all the dirt, salt and water under there, unless you could mount it in a box.

2. Wire another switch for this circuit and just forget the dash switch. If you have your manual valves say, behind the driver's seat in the floorboard, you could mount a electrical switch to switch the sending units also. You could put it inside the cab in a safer place, and the wiring would not be that far away from the original location of the valve.

Looking at the above, I suppose you could add a relay and mount it inside the cab near the rear floor area and still use the dash switch.

The original valve had a little motor in it. The dash switch is more like a power window switch. It is wired to switch the polarity of the voltage going to the valve motor, making it switch direction to switch tanks. So there is only two wires going from the dash switch to the valve, that is not much help in switching the sending units unless you use a relay.

Really like the relay idea, basically use the normally open circuit for one sending unit and the normally closed for the other is what I'm understanding. Wonder if i can find all the required wires in the connector on the selector valve and use the 12v from one of the directions on the dash switch.

 

[franklin2]

Really like the relay idea, basically use the normally open circuit for one sending unit and the normally closed for the other is what I'm understanding. Wonder if i can find all the required wires in the connector on the selector valve and use the 12v from one of the directions on the dash switch.

All of the required sending unit wires are at the valve. And you could use one of the motor wires to the valve for the relay. Depending on the position of the dash switch one of the motor wires will be ground, the other will be 12v. Move the dash switch and the 12v moves to the other wire and ground moves to the other wire.

So you could choose one of the motor wires, and just ground the other side of the relay coil to a good metal ground somewhere. The one motor wire will be 12v or ground depending on the dash switch position. The other side of the relay coil will always be ground if it's grounded to metal.

 

[clayhwalker]

So I really like this idea of using a relay. I don’t suppose one of you electrically intelligent people could make a diagram for me could you? I can follow a diagram somewhat but I just wanna make sure I hook things up right. Even just a hand drawn little something would work well.

 

[IDIBOBS]

Just put it back to stock. The stock system works fine. Works great. Cheap and easy to replace. Why jack up a truck for more head ache when you could put it back to stock and have it work fine for another 100-200 plus thousand miles. This is a band aid.

 

[Jesus Freak]

So I really like this idea of using a relay. I don’t suppose one of you electrically intelligent people could make a diagram for me could you? I can follow a diagram somewhat but I just wanna make sure I hook things up right. Even just a hand drawn little something would work well.

You're just gonna have to get under there and and start diddling.

I messed around and figured out which 2 things to jumper so I know what's in my rear tank, which is the only one that matters to me. My returns go to the rear and my front tank is clean diesel for shut down with no return going to it. I'm sure with patience someone could figure out who's who on the couple of wires down there. Or you could just leave a working factory valve in place and route your fuel through the manual valve.

P.S. I love my manual valve.

 

[clayhwalker]

I think that’s what I’m gonna do. I ordered an inexpensive Chinese valve from Amazon and basically I’m just gonna keep it capped off and use it for the electronics. I wanted the manual valves because I ran half inch lines. I did a Cummins swap that I’m turning up pretty good. Wanted to make sure I have plenty of fuel for my hot rod fuel pump.

 

[franklin2]

You must be registered for see images attach