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.
What does 0.1 mean on a fuel pump meter?
If the meter indicates a reading of more than 0.1 then this indicates a loss of voltage power. The reason for the loss could be damaged harness connectors or poor wiring. Connect the digital multimeter to the positive terminals of the pump and the battery.
What does it mean when the voltage drops on a fuel pump?
If the voltage drop is greater than the recommended reading of 0.1 volts then this is a confirmation that indeed the harness connectors or the wiring is faulty. You need to locate the exact location of the fault to correct the problem.
Why does my gas tank keep shutting off?
Spent today under the car pulling off the old evap canister and then proceeding to put compressed air through the lines to remove as much charcoal particles as I could. Got everything connect back together and went to fill up. Issue remains. Can get about 1.5 gallons in the tank before it shuts off.
Where is the fuel pump fuse on a GMC Sierra 1500?
You only have a yellow 20 Amp fuse in the upper far right corner of the fuse box panel under the hood. Extra tip: replace your oil pressure switch. It way in the back of the motor. You need a 27mm deep well socket, 3/8 drive and a stubby flex ratchet, small hands help too. 3 people found this helpful.
How do you test a fuel pump amperage?
Clamp the probe to one of the pump wires, if it’s accessible. Or clamp it around the pump’s power wire at the fuse box, at a relay or inertia switch or at an underhood test connector. While voltage may be different at various points in a circuit, current in a series circuit is the same at all points.
Where is the fuel pump fuse box located?
Remember: There is nothing in the fuse box marked [Fuel Pump] location. Because you have a ECM electronic control module. You only have a yellow 20 Amp fuse in the upper far right corner of the fuse box panel under the hood. Extra tip: replace your oil pressure switch. It way in the back of the motor.
Is the fuel pump fuse no power on a 1990 Chevy?
Took a test light and found the fuel pump fuse has no power to it. Took my test … read more I have a 1990 chevy pick up trk 1500 , 5.7 engine.
How can I check the voltage of my fuel pump?
Establish the location of the fuel pump relay on the dashboard or the engine compartment. Remove the relay and have some one switch on the ignition without starting the engine. Check for voltage at the relay connector using a digital multimeter.
Is there any power to the fuel pump relay?
Truck has sat for 6 mos or so. Has always started before. Using a simple test light there is no power at all to the fuel pump fuse. Replaced the fuel pump relay just to be safe. Still no power to the … read more
What kind of fuel pump did a 1990 Chevy k1500 have?
1990 chevy k1500 truck (5.0). Power at orange wire of fuel pump relay but pump won’t run. No power to any of the other 1990 chevy: Power at orange wire of fuel pump relay but pump wont run…
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.
Can a voltage drop test be done on a fuel pump?
TESTING VOLTAGE DROPS. A voltage drop test is the only effective way to find excessive resistance in high-amperage fuel pump circuits. With the right leads and back-probes, it’s possible to do the test (if you have access to the top of the tank) without any disassembly.
What happens when you lose 4.0 volts on a fuel pump?
The loss of 4.0 volts may not affect the idle of a vehicle, as the fuel pressure may be within specifications. But, when more volume is required, as when the vehicle is under acceleration, it could be starved for fuel. It doesn’t take much to introduce 0.5 ohms or more of resistance into an automotive electrical circuit.
Why do I only get 5 volts at the fuel pump?
When I turn the truck on the pump will not turn on and prime and the voltage always stays at 5 volts if the key is on. Any idea guys? If were to dis-connect the pump and sending unit, do you get 12v at that leading wire. That is what I did and got only 5 volts
What is the 4 prong connector for a fuel pump?
The 4 prong connector is for the fuel pump and sending unit. The gray wire on that 4 prong is the power for the fuel pump. I was checking the 3 prong connector. I am going to do some further test and will respond with what I find. Thanks again guys. dstites wrote: Thanks everyone for your responces.
TESTING VOLTAGE DROPS. A voltage drop test is the only effective way to find excessive resistance in high-amperage fuel pump circuits. With the right leads and back-probes, it’s possible to do the test (if you have access to the top of the tank) without any disassembly.
What kind of wire to run fuel pump?
You can run a wire from the (power) red side on the battery to the fuel pump gray wire and a ground to the frame to test the pump and wiring issue. Just a thought.
Can a fuel pump shut off switch wear out?
The fuel pump switch is an electrical component, and just the same as the rest on the vehicle, over time it can wear out and develop issues. As the switch has the capacity to shut off the fuel pump, issues with it can potentially lead to drivability and performance issues for the vehicle.
What makes a fuel pump have a low voltage?
The only items in this circuit are the fuse, the relay, the inertia switch, and the pump. Low voltage to the pump can only be from a low voltage at the source or a resistance in the circuit (“dropping” voltage).
Where is the inertial fuel shutoff switch located?
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.
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.
What should the voltage be on a fuel injector?
The wiring harness will have two terminals that the prongs on the injector insert into. One will be connected to ground and will read 0 volts. The other should read around 12 volts. Step 5: Repeat with all injector wiring harnesses. Leave the ground lead in position and test all of your injector wiring harnesses. They should all be around 12 volts.
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.
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.
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.
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.
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.
The only items in this circuit are the fuse, the relay, the inertia switch, and the pump. Low voltage to the pump can only be from a low voltage at the source or a resistance in the circuit (“dropping” voltage).
How do you clean a fuel pump relay?
Since any debris will affect the fuel pump relay’s performance, you should regularly inspect and clean it when necessary. The fuel pump relay is an electrical car part, thus be extremely careful when handling a relay. First, take off the relay and use the blower to blow off dirt and dust for about 1-2 minutes.
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.
Is the fuel pump relay controlled by the PCM?
Consequently, the fuel pump relay is usually controlled by, the ignition or powertrain control module (PCM). As a result, when switched on, the fuel pump relay; will provide current to the fuel pump, so that it may function. Therefore, any faults with it, can cause fuel pump issues.
What is the high current circuit on a fuel pump?
The high current circuit is the one that delivers the voltage (and thus current) to the fuel pump in the gas tank (or on the frame rail). When the fuel pump relay is off (not activating the fuel pump), the high current circuit is ‘open’.
Consequently, the fuel pump relay is usually controlled by, the ignition or powertrain control module (PCM). As a result, when switched on, the fuel pump relay; will provide current to the fuel pump, so that it may function. Therefore, any faults with it, can cause fuel pump issues.
Is there no power to the fuel pump?
No power to the fuel pump and the fuel relay is not getti… Q: No power to the fuel pump and the fuel relay is not getting power. My car has 190000 miles.
Why is my fuel pump relay not working?
Most of the time, if I leave the key in the On position, after several seconds to a few minutes, it will all of the sudden prime and the gauge comes alive. Then it will work for a few days until the next time it randomly doesn’t. I have ruled out the Passkey issue. The fuel pump relay works as it should. I always have power to Pin 30.