Where is the dual tank balance module located?

This module is located by the front (main) lift pump. Slightly toward the rear of vehicle along the frame rail. On top of this module is a fuel pump balance relay, it turns the rear pump on as needed to transfer fuel. At the module, you have a harness with 6 wires. Unplug it and check the following with a digital volt/ohm meter

Why does my gas gauge go from full to empty?

This will send the crazy signal to the fuel gauge. This would be the time you see the gauge going from full to empty on it’s own, or usually after you fill up your vehicle it will act up from the sloshing around of the gasoline. This can get quite annoying, and will leave you not knowing how much fuel you actually have.

How does the fuel gauge work on a car?

There is also a fuel level sensor, or you may know it better as a ‘sender’. It holds the float assembly along with a resistor board that has small little metal ‘fingers’ that touch the board and send the signal to the fuel gauge to display the proper amount of fuel in the tank.

What is the resistance of a fuel gauge?

The level sensor in the fuel gauge sender produces a resistance of about 40 ohms (Gas)/0 ohms (Diesel) empty and about 250 ohms (Gas)/90 ohms (Diesel) full. A short to ground in the sender or the wiring provides a fully empty indication. An open in the circuit provides completely full indication.

What should I do if my fuel tank is plugged?

If these conditions are found, replace the fuel tank and fuel pump module. Refer to Fuel Tank Fuel Pump Module Replacement in the appropriate Service Information. In addition, to help prevent the vent from becoming plugged again, install a piece of fuel hose to the vent (Fig. 15, #1) and route it down the fuel feed line.

Where is the fuse on the fuel tank?

Fuse is in underhood fuse/relay center marked IGN E 10 AMP Terminal B- Light Blue wire, this is the signal wire from the secondary (rear) fuel tank, using an ohm meter, measure the resistance from a good chassis ground to this wire and should get a reading between 0 and 90 ohms, 0 is empty tank and 90 is full.

How does the fuel balance pump in a Chevy truck work?

The low pressure, about 32 kPa (7 psi) fuel balance pump is used only to transfer fuel from the auxiliary tank to the main tank in order to balance the fuel levels in both tanks. As the main tank level drops to about 25 percent below the level in the auxiliary tank, the fuel sender and balance module energizes the fuel pump relay.

Can a fuel balance module bypass a VCM?

You cannot bypass either sender direct to VCM, Fuel Balance Module takes both readings and converts to a voltage from a VCM 5volt referance. The transfer pump will not operate unless primary fuel pump in front tank is running and Fuel Balance Module sends a ground to relay located on same bracket.

How does a Chevy truck’s dual fuel tanks operate?

Any malfunction in either of the fuel gauge circuits will disable the system and the fuel will not be transferred from the auxiliary fuel tank to the main fuel tank. Loading…

Where is the balance relay on a truck?

Slightly toward the rear of vehicle along the frame rail. On top of this module is a fuel pump balance relay, it turns the rear pump on as needed to transfer fuel. At the module, you have a harness with 6 wires. Unplug it and check the following with a digital volt/ohm meter Terminal A- Pink wire, should be 12 volts with key in run position.

How does the fuel pump balance module work?

The Fuel Pump Balance Module sends out a fuel level signal to the senders through either CKT 970 (DK BLU/WHT) for the Primary Sender and CKT 975 (LT BLU) for the Secondary Sender. Ground for both senders runs through CKT 900 (BLK) to the VCM.

Why are there two gas tanks in my GMC 3500?

Gmc Two Gas Tanks Why No Selector Switch. Hows It Work? My 02 GMC 3500 Dump fuel gauge is broken. The gas gauge shows E and the fuel message board says low fuel. It has two gas tanks but no selector switch, and it seems to pull gas from both sending units at the same time, while keeping track of the total fuel amount.

Why are there two gas tanks but no selector switch?

It has two gas tanks but no selector switch, and it seems to pull gas from both sending units at the same time, while keeping track of the total fuel amount. I tried installing a new sending unit in each tank, but that didn’t solve the issue.

Can a GM Truck have two fuel tanks?

Yes, each tank has its own filler. Oddly there is only a single fuel guage that seems to report the total fuel of the two tanks combined. For instance, if I were to fill one tank and leave the other empty, the guage would read about half full.

How to switch fuel tanks on 1997 K3500?

Vocational, Technical or Tra… How do you switch fuel tanks on a 1997 K3500 with dual tanks. I can not find a switch anywhere. I was told the switch automatically.

What’s the difference between front and rear gas tanks?

On vehicles with dual tanks, the front tank is the main and the rear tank is the auxiliary. The main fuel pump supplies fuel to the fuel injection unit. The low pressure (about 32 kPa or 7 psi) fuel balance pump is used only to transfer fuel from the auxiliary tank to the main tank in order to balance the fuel levels in both tanks.

Why is my fuel tank selector not working?

The selector valve has problems, and the fuel tank will not open or close. The selector valve doesn’t work in the starting position. Fuel system problem. Overfill of the fuel tank. It’s a widespread problem for the ford fuel tank selector valve.

How does a gas tank work with two tanks?

As the tank switch is pressed to seat for the the other tank, the valve switches over to close the fuel port for the previous tank and open for the selected one. Simultaneously, the contact (s) for the sender opens for the previous tank and closes for the selected tank.

What happens when you turn off the relay on a gas tank?

Contacts in this switch close and send 12 volts to the fuel pump. The system will stay in this configuration until you turn the key off or the engine looses oil pressure. The 3 second operation of the fuel pump by the relay is to prime the fuel system, this makes the engine easier to start.

What to do if your truck has dual fuel tanks?

If it’s acting up on a regular basis get it to a technician. It should be a quick confirmation with the appropriate wiring diagram and a digital volt/ohm meter. Here’s a little trivia on a somewhat relative recall pertaining to ’90-’93 F-series trucks equipped with dual tanks.

Why is my Ford F250 dual fuel tank problem?

This kit was issued by Ford to prevent two problems: fuel flowing from one tank into the other through the supply lines, and long cranking times due to fuel running back into the tanks after the vehicle was shut off. The pressure regulator was included as good practice. In my case, I had the two valves and the pressure regulator installed.

Why is my fuel tank switch not working?

When you select the rear tank it does the opposite, and hooks up the pump and sending unit in the rear tank. It sounds like there may be bad contacts within the fuel tank selector switch causing you grief. If it’s acting up on a regular basis get it to a technician.

How is the fuel pump connected to the front tank?

When you’re in “front tank mode” the selector switch sends 12 volts to power the electric fuel pump in the front tank. At the same time it connects the fuel gauge sending unit in the front tank to the fuel gauge in the instrument cluster. When you select the rear tank it does the opposite, and hooks up the pump and sending unit in the rear tank.

What happens when you switch from front to back tank?

The problem I am experiencing is when I switch from the front to the back tank, the gauge switches to indicate a full tank like it should, but within a few miles the gauge reads empty and the front tank reads full. Also, the truck begins to act as if it is out of gas. The problem has to be, or at least related to, the fuel tank selector switch.

Where is the dual tank balance module located?