The main reasons why your starter fuse keeps blowing are battery issues, a bad starter relay, a faulty ignition switch, a damaged starter solenoid, a faulty starter, wiring issues, and a malfunctioning fuel pump.
Keep reading this article to find out more about these issues in detail and how you can fix them to keep your starter fuse from blowing again. Let’s jump in!
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Why Car Starter Fuse Keeps Blowing [Reasons + Solutions]
If you’re wondering what would cause a starter fuse to blow, you’ll find the answer in this section. Let’s look at the most common reasons why it happens:
1. Battery Issues
One of the most common reasons your starter fuse keeps blowing is battery issues. If the battery is dead or has a bad ground, it’ll draw too much current that the fuse won’t be able to handle. That’s why your 30 amp starter fuse keeps blowing.
Check both the positive and negative terminals of the battery using a voltmeter. By looking at the readings, you’ll know if the battery is okay or not.
Sometimes, the battery will be fine but it’ll be low on charge and cause trouble. Recharge the battery to bring it back to life when that happens.
If the battery has a terrible ground, you can replace the battery ground wire to fix the problem. But if it’s dead, you should replace it rather than try to fix it. It doesn’t cost much to replace the battery and you can do it yourself.
2. Bad Starter Relay
Another common reason that causes your starter fuse to keep blowing is a damaged starter relay. It’s easy to diagnose if your relay is functional or not. Have someone start the car and place your hand on the starter relay once you’ve located it.
If you hear a clicking sound, it means that your starter relay is working. Otherwise, it has gone bad or the connection is loose. Take it off, clean it with a dry towel, and put it back in. If it still doesn’t work, that means it is damaged.
You’d have to replace the damaged starter relay with a new one. It’ll only take a minute if you’ve already located it. Starter relays can cost anywhere between $2 to $50 depending on your vehicle.
3. Faulty Ignition Switch
If you’re noticing starter fuse blown symptoms in your car, it could be due to a faulty ignition switch. It could be shorting by drawing excess current from the battery that is too much for the starter fuse to handle and it gets blown.
You can check if the ignition switch is working properly or not using a good quality voltmeter and examine it for continuity. If there’s no continuity, that means it’s damaged.
The ignition switch needs to be replaced to prevent the starter fuse from blowing. Replacing the ignition switch can cost you a few hundred dollars if you factor in the labor costs of the mechanic.
4. Damaged Starter Solenoid
The ignition switch feeds power to the starter relay which transfers the power to the starter solenoid which goes to the starter motor and causes the car to start. So, a damaged starter solenoid can be drawing too much current from the battery and can cause the fuse to blow.
The starter solenoid needs to be replaced if it’s damaged. The starter solenoid gets attached to the starter in the newer vehicles but it could come as a separate unit if you use an old car. Replacing the solenoid will keep your starter fuse from blowing if it was causing the issue.
5. Faulty Starter
If you’re sure that you’re battery is good, the next thing to check is the starter. A faulty starter could be the reason why your starter relay fuse keeps blowing. The wires leading to the starter can also get corroded and cause it to draw too much amperage. It can also lead to a blown fuse.
The starter motor can also become faulty and blow the fuse. It usually happens when a gear connected to the flywheel has been dislodged or badly stripped from the flywheel.
You can clean the wires if there’s corrosion on them and they’re the reason why the starter isn’t working properly. If they’re too corroded and seem to be beyond cleaning, replace them and that might get your starter to work properly. Otherwise, the issue is with the starter itself.
Regardless of whether only the starter motor or the starter has gone bad, you’d have to replace it with a new one. Starters can easily cost between $100 to $400 if you get a new one.
You’ll also have to add labor charges to that if you take it to a mechanic. But the good news is that you can replace the starter yourself if you’re up to the challenge. Follow these steps to replace the starter:
- Locate the starter in your car.
- It’s usually located under the car.
- Use jack stands to lift the car if you have to work underneath it.
- Disconnect the negative terminal of the battery to make sure that no power goes to the starter.
- Unscrew the bolts that are holding the starter in place.
- Remove the wires connected to the starter but make sure you remember their positions.
- Once you remove the wire connections, you can pull the starter out.
- Clean the wires before you put in the new starter.
- Put the new starter in place and connect it to the wires.
- Add some silicone paste to the wires to prevent corrosion.
- Screw the bolts and make sure the starter is secured.
- Put thread locker to prevent the bolts from getting loose during vibration.
Now you’ve successfully replaced the starter. Bring it down, connect the battery, and see if the starter works properly without blowing the starter fuse.
6. Wiring Issues
A short circuit in any one of the wires is a common reason that causes starter fuses to keep blowing. A hot wire can cause the fuse to blow immediately when it’s installed. But when it gets blown when you crank it, chances are it’s one of the wires located between the ignition switch and the starter relay.
Having a wiring diagram of your car would greatly help you to diagnose a wiring issue. It’ll show you the entire circuit and you can trace it with a Voltmeter or Ohmmeter and check for continuity.
If you don’t have the wiring diagram or it’s difficult for you to diagnose the wiring in your car, take it to a mechanic and have him go through the wiring system. If there are any issues with it, he can easily fix them.
7. Malfunctioning Fuel Pump
If you’re still wondering why my starter fuse keeps blowing, another common reason behind it is a faulty fuel pump. It can also draw too much current from the battery and make your starter fuse blow.
You can check the fuel pump by checking the fuel pressure from the port on the top of the engine if you have a fuel pressure gauge checker. Connect the checker to the port and crank the engine. If the pressure doesn’t increase when you do that, it means you have a bad fuel pump.
If you’ve successfully diagnosed a faulty fuel pump, you need to replace it. Unfortunately, replacing a fuel pump can be very expensive and can cost around a thousand dollars depending on where it’s located in your car.
What is a normal amperage for a starter fuse?
Starter fuses normally range from 10 amps to 30 amps. Whenever the current in the circuit exceeds that amount, the fuse is designed to blow and stop the circuit.
Where is the fuse for the starter?
The starter fuse is located in the fuse box in most vehicles. It’s the big black box that you see next to your engine when you pop the hood of your car.
Why does the ignition relay keep blowing?
When the ignition relay keeps blowing, it indicates a faulty ignition coil or wiring issues in the ignition module. Replacing the ignition coil or fixing the wiring problems will keep the fuse from blowing.
What happens when the starter relay fuse blows?
Your car won’t start at all when your starter relay fuse is blown even if you try doing it multiple times. You won’t even hear the clicking sound your car normally makes when this fuse is blown.
It’s extremely frustrating when your starter fuse keeps blowing even after replacing it multiple times. But now you know what are the most common reasons that cause it and how you can fix them.
We hope that you can address the root cause that’s causing your starter fuse to blow by following this guide rather than guessing randomly. Leave a comment below if you have any more questions about starter fuses.