What can cause a system to lose control voltage?
When corrosion, loose connections or other types of resistance restrict a circuit, volts and amps both drop. If volts drop, amps drop too. That is why when you find a voltage drop in a connection or cable, you know the connection or cable is restricted.
Can a fuel pump have a voltage drop?
Fuel pumps and voltage drops are never a good combination – at least the wrong kind of voltage drops. Good voltage drops occur with fuel pumps that are given multiple speeds with a module that is connected to a computer with a dedicated signal wire that tells the module to go to a lower or higher speed.
How can I control the speed of the fuel pump?
Either way, we can control fuel pump speed by reducing the voltage, or by turning the fuel pump off and on with a pulse width-modulated output. These types of voltage drops are fine because we want the fuel pump to run at different speeds based upon the engine’s demand for fuel.
What causes a fuel pump connector to go bad?
One of the most common reasons for a connector to go bad is the retention clips. If a connector does not have good retention and a tight connection, it can lead to heat problems. Corrosion on terminals has been an issue recently due to the location of the connector on the tank.
How much voltage needed at fuel pump battery?
Sounds like your dad is checking the fuel level sensor circuit. fuel pump voltage should be close to battery voltage. Sounds like your dad is checking the fuel level sensor circuit. Click to expand…
Where does the voltage come from in a fuel pump?
This voltage comes from the EEC Power relay. Power (in the form of 10 to 12 Volts) is applied to circuit 4 . This voltage comes from the ignition switch. The fuel injection computer then grounds circuit 1. This activates the fuel pump relay to pass current from circuit 4 to circuit 3.
How many volts do you need to flip the switch on a fuel pump?
This must be over 10 volts to flip the switch in the relay. This will confirm whether or not the ECM is telling the fuel pump to run. 2. Check for continuity from the tan/white wire at the relay to the fuel pump. This will determine if power can get from the relay to the fuel pump.
How is circuit 3 connected to the fuel pump?
Circuit 3 is the one that runs to the fuel pump (via the Inertia Switch) and delivers the voltage/current it needs to activate. Before this voltage reaches the fuel pump, it has to go through the fuel pump Inertia Switch first. If the Inertia Switch has been tripped, it will ‘open’ the circuit and the voltage will not reach the fuel pump.
Why are heavy duty connectors used in a fuel pump circuit?
Voltage in the circuit is reduced “downstream” of the high resistance, so this reduces the voltage that reaches the pump motor. That’s why heavy-duty connectors are used in a fuel pump circuit. There are two fuel pressure specifications for every vehicle: system pressure and hold pressure.