Fuel pump problems are not uncommon on older vehicles that have been driven hard or subjected to rough conditions. The fuel pump relay is a small, inexpensive part that controls the flow of electricity to the fuel pump. If this part fails, the vehicle may run out of gas and fail to start due to no fuel being delivered by the engine.
The following steps will help you troubleshoot and repair your vehicle’s fuel pump relay problem, but first, let’s take a look at the causes of no power to the fuel pump.
1. Bad Fuel Pump Relay
If you suspect the fuel pump relay, start by checking the fuse. If it’s blown, replace it with a new 15-amp fuse and see if your car starts. If so, you know that the problem lies somewhere else in the electrical system.
If the fuse is not blown and your car still doesn’t start, proceed to test your fuel pump relay by removing it from its place under the hood of your vehicle. Use an ohm meter (also known as an electrical multimeter) to check for continuity between each terminal on both sides of this relay—if there is none then it has probably gone bad and must be replaced.
This is a common failure point for fuel pumps: they run 24/7 so they often burn out over time due to excessive heat buildup or just plain old age; either way, they need replacing now and again.
2. Bad Ignition Switch
If the ignition switch is bad, it can cause your fuel pump to stop working. This would make it impossible for you to start your car and drive anywhere. In this case, the best thing to do is get a new ignition switch installed by a mechanic or at your local auto parts store. This can be done with very little effort and expense, so there’s no reason not to try it.
3. Bad Ignition Switch Actuator Pin
The ignition switch actuator pin is the link between your ignition switch and your ignition coil. When you turn the key in your ignition switch, it pushes this small metal rod through a hole in your key and makes contact with your ignition coil. This causes power to flow to all of the other components that need it, including your fuel pump.
The bad news is that if these two parts aren’t working together properly, nothing else will work either—including starting up your car. The good news is that they are both easy enough to replace yourself if they break or get lost.
4. Bad Fuel Pump Fuse
If your car has a lot of electrical components, and especially if those components have been in use for a while, there is the chance that they might not be able to handle all that power at once.
This can cause them to burn out or overload themselves with too much electricity. For this reason, relays are usually placed strategically throughout your vehicle so they can regulate how much power flows through certain circuits.
The fuse that controls your fuel pump also prevents overloading by keeping things running smoothly until it’s time for them to be shut off again—it allows electricity into the loop only when needed. But if something goes wrong with this process—if something causes an interruption in how long the circuit remains open or the fuse gets blown you’ll end up having problems with starting your car.
5. Bad Fuel Pump Relay Socket
The relay socket is a small plastic box with a set of contacts. If the contacts are damaged or broken, it can make the fuel pump have no power.
6. Faulty or Broken Wires
The next thing to check is the wiring harness. This is a common problem and can cause your fuel pump not to work. You will want to check the following things:
- Check for damage to the wiring. If there are any tears or rips in the insulation, this will allow water or contaminants into your system and could eventually damage components like a fuel pump.
- Check for loose connections. Sometimes wires get bumped out of place when you’re working on something else, so make sure that all connections are tight and secure before starting up your vehicle again. A loose wire connected incorrectly could lead to overheating in your system which would then damage components such as a fuel pump if left unchecked long-term.
7. Bad ECU or PCM Systems
The ECU and PCM systems are responsible for the fuel pump relay, fuse, and socket. If these are not functioning properly, then you may have a problem with your power source. This is also a good sign that your ECU or PCM systems need to be replaced.
How to Fix the Problem
1. Fix Broken Wires
If your fuel pump isn’t working and you’ve checked all the fuses, the problem may be in the wiring. To figure out if this is true for you, check to see if there are any frayed or broken wires anywhere in the car’s wiring harnesses. If there are, then proceed with replacing them.
Unplug the wire from its fuse box connection or another component terminal, then unplug from the connector. Take a wire brush and clean off any corrosion on the connector ends. The corrosion can cause poor electrical contact between them so make sure everything is nice and shiny before reconnecting them together again.
2. Replace the Bad Fuel Pump Relay
A fuel pump relay is a sealed unit that contains the electronic components the fuel pump needs to operate. In most cases, you can find it by looking in your owner’s manual or under the hood of your car.
You can test a bad relay by disconnecting the battery cables and seeing if your car will start. Replace it with an identical new one. After replacing any relay, make sure to test that everything works properly before reconnecting them.
3. Replace the Blown Fuse
Remove the negative cable from your battery. Open your fuse box and replace the blown fuse with a new one with the same amperage rating.
If everything checks out OK so far, reconnect your negative cable to your battery and test that all fuses are still in working order by checking them at least once a week after that point.
4. Repair or Replace Faulty Parts of or Bad ECU or PCM System
If you have determined that it is not the fuel pump, then you may want to check the ECU or PCM system. The ECU controls the fuel delivery and other functions in your vehicle. It can fail without warning and cause a no-start condition or a rough-running engine.
To test this, disconnect all cables from the PCM/ECU connections on top of it. Then, start your vehicle and let it run for at least 10 minutes with no faults present before stopping again as this will help in testing if there are any problems with your electrical system(s). If there are any issues found with either one of these components replace them immediately because they will continue causing problems until they are replaced completely.
Conclusion
If you don’t see power, it may be a bad fuel pump or a bad fuse. I would recommend starting with checking the fuses and relays first. If that doesn’t help then check your connections to make sure they are clean, tight, and not corroded. If all looks good then it could be time for new parts.