Starter Engages When Battery Is Connected

Few things are as frustrating as when your car or truck will not start. It costs you time and money trying to figure out what is wrong. If you are lucky, you narrow it down to a dead battery.

But what if after you replace the battery you have a different problem arise? Sometimes you may find that your starter is engaging, even though you aren’t turning the ignition key. What causes this to happen? And what can you do to fix this?

How do the starter and battery work?

In order to understand the possible problems with your starter, you need to understand how it all works. The starter has a terminal that connects it to the battery. There is also a smaller terminal on the starter. This smaller terminal is the ignition switch that kicks the solenoid to engage the starter.

What to do if your starter stays engaged?

If you have replaced your starter, you may find you have this problem. If your starter engages when the battery is connected, but you aren’t turning the ignition key, you need to check a few things out. This is an issue that must be resolved.

1. Over tightening

It is possible that you have over tightened the post on the smaller terminal. This is the terminal that signals to the solenoid to start the ignition. When this happens, the starter is getting the signal to start all the time.

It is very possible that when you over tightened the screws, and this has also cracked the solenoid case. You will need to replace these parts.

What are some other reasons why my starter stays engaged?

1. Oil or fluid leaks. If your car is showing any signs of having fluids or oil leaks, this could be causing an internal problem. Often times these kinds of leaks can and do ruin parts of the engine and can lead to fires. This type of corrosion can lead to starter issues.
2. Loose mounting. It is crucial to check the mounting if you have recently replaced your  starter.
3. Over tightening. If you are installing a new starter yourself, you should not use an impact wrench.  You should only hand tighten the bolts on the starter. And when you are tightening them, be sure to alternate bolts as you work. This will help prevent over tightening and cracking of the mounting.
4. Broken Gear. If your ignition switch is faulty, it is possible that this has happened because the pinion gear has had improper contact with the starter ring gear. You would see that the pinion gear has severely damaged teeth all the way around it. This can also happen if you are trying to crank the engine, and it is already running.
5. Poor Grounding. Mounting bases are crucial for starters to work correctly. They provide the electrical ground path to the starter. It is important that are clear and shiny. This ensures a smooth circuit.
6. Loose electrical Connections. If the electrical connections are not securely fastened to the starter from the battery, the result can be arcing and burning.
7. Melted terminals. If there is cranking of the engine, it can cause the terminals to overheat and melt. These terminals will need to be replaced.

It could be the starter solenoid.

The starter solenoid in your car is a relay. When you start your car, the battery sends electricity to the starter solenoid. The solenoid then waits to receive a signal from the ignition switch when you turn the key.

When voltage from the battery is sent to the solenoid, a switch is closed inside the solenoid and a current is sent to the starter.

So, how does the solenoid go bad?

There are 4 reasons why a solenoid goes bad. If any of these things have happened or you notice them, you will need to replace your solenoid.

Moisture

Once moisture gets inside the solenoid, it leads to corrosion. When this happens, it affects the electrical conductivity.

Overheating

When you turn your ignition key, it creates heat because the electrical current is pulled through. If you hold the ignition switch on for an excessive amount of time, this causes the contacts to melt.

Overtightening

Again, overtightening when replacing the starter can cause damage to the starter. Make sure you do not use an impact wrench when replacing this part.

Incorrect Wiring

If you install the solenoid wrong, this can cause it to short out. When this happens, there will be internal damage to the wires.

Things to Remember

There is nothing more frustrating that a car that has trouble starting. And even though you may replace components such as battery and starter, you can still have an issue.

Having your car constantly engaged is also a problem. Your vehicle should only engage when you have turned the key. If it is happening without you doing this, there is a problem. Often times the problem is a faulty starter or solenoid. This is a repair you can do yourself with a few tools and a new part.

You should be careful if you are replacing your starter. You do not want to use an impact wrench. This will cause you to overtighten, and overtightening can cause cracks and damage.

Another problem to check for is damage due to moisture. If you notice excess moisture under the hood, this can lead to corrosion which causes the electrical conductivity to suffer.

Be sure to thoroughly check for loose connections from your starter terminals to your battery. Make sure that no wires are melted, damaged or loose.

Final Thoughts

There is nothing more frustrating than a car that won’t start, except perhaps a car that is always started. However, with a little bit of under the hood detective work, you can take steps to figure out the root cause. Just be sure to use care when handling your starter and be mindful of electricity.

Hopefully you will have your car back to starting and stopping, correctly.