Where does the current from the fuel pump relay come from?
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. Circuit 3 is the one that runs to the fuel pump (via the Inertia Switch) and delivers the voltage/current it needs to activate.
How much voltage is needed at fuel pump?
No voltage when starting until ecm sees oil pressure, see above. Purple and black with white stripe are your fuel level sensor, gray and black are fuel pump. So this ‘needing oil pressure to pump fuel’ seems a bit suspicious to me. It drove home fine the other day after fixing a loose wire at the relay, but now it magically won’t start.
How to test a suspect fuel pump relay?
1 The easiest way to test a suspect fuel pump relay is to; swap the suspect relay with a good one. 2 You may find another relay in your car with the same configuration as your fuel pump relay. Just make sure the other relay has the same configuration. 3 Remove the suspect relay and install the good relay and check if your engine fires up. …
Is the Ford fuel pump relay a green color?
If your fuel injected Ford pickup, van, or car still has the Ford relay, this bad boy will be a green color (like the one in the image viewer). If it has already been replaced with an after-market one, this relay won’t be green, but will have a gray body.
What should the voltage be at the fuel pump relay?
You should have 12 volts at the dark green/yellow wire at the fuel pump relay. The inertial fuel shutoff switch is between the relay and the fuel pump. The pink/black wire from the inertial switch to the fuel pump should have 12 volts. You can measure the voltage, on the pink/black wire, at the fuel pump.
Where is the fuse for the fuel pump?
The fuse is called: Fuel System/Anti-theft Maxi-fuse. It’s under the hood, in the fuse/relay box. You are getting voltage, so, the fuse is ok. You should have 12 volts at the dark green/yellow wire at the fuel pump relay. The inertial fuel shutoff switch is between the relay and the fuel pump.
Where does a low voltage fuel pump come from?
Low voltage to the pump can only be from a low voltage at the source or a resistance in the circuit (“dropping” voltage). The only possible places for a resistance are connections (which could be anywhere including a corroded fusebox terminal), relay contacts corroded (but you’ve already changed that) or internal to the inertial switch.
What are the symptoms of a bad fuel pump relay?
A bad fuel pump relay can cause many different symptoms. Here are the most common ones The fuel pump relay is an important component of the fuel system of your vehicle. The fuel pump relay gives the fuel pump power when it is time to build up fuel pressure in the rail.
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. Circuit 3 is the one that runs to the fuel pump (via the Inertia Switch) and delivers the voltage/current it needs to activate.
How to test a fuel pump relay with a multimeter?
1 Turn off your vehicle and remove the key from the ignition. 2 Find the fuel pump relay in your vehicle’s fuse box. 3 Pull the relay straight out from the fuse box to remove it. 4 Clean the relay prongs with a wire brush. The fuel pump relay may be faulty or have a loose connection if it’s developed any rust or corrosion on the
How do you remove a fuel pump relay?
Grab the relay firmly on either side and pull it straight up and out from the terminals of the fuse box. If the relay doesn’t pull out right away, try rocking it back and forth to loosen the connection. You won’t be able to start your engine after you remove the relay because the fuel pump won’t work.
If your fuel injected Ford pickup, van, or car still has the Ford relay, this bad boy will be a green color (like the one in the image viewer). If it has already been replaced with an after-market one, this relay won’t be green, but will have a gray body.