Your car can fail to crank and start for several reasons related to problems with the car starter – worn-out pinion, starter brush wear, or even a burnt-out starter!
In this post, I cover the 6 key points to help you understand the causes of starter burnout so that you can avoid them, the symptoms of starter burnout so that you can recognize them immediately, and the tests you can do to confirm burnt out starter
1. Can a Car Starter Burn Out?
While some starters can have a long service life, a car starter can burn out from the excessive heat caused by repeated attempts to start and other reasons.
This damages the starter components – the magnetic switch, windings, internal springs and affects the starter’s ability to crank and start the car engine properly.
What happens when a car starter burns out?
When a car starter motor burns out, you can recognize any or a combination of the following signs on a starter.
- The magnetic switch contacts can burn out
- The coating of the wire on the car starter armature may melt
- The pinion gear may only partially retract because of return springs damaged by the excessive heat.
It should be a full retraction to switch off power to the starter motor and disengage the starter motor from the car engine.
All of this results in the car starter failing to rotate or crank the engine at all.
You may also want to read: Can a car starter drain a battery?
2. Causes of Car Starter Burn Out
Your car’s starter can burn out from a combination of improper usage and failure of key components as described
Holding the ignition key in the start position for a long time
This is probably one of the main reasons why car starters burn out. Holding the ignition key in the start position for a long time, 10 + seconds, repeatedly without allowing the starter to cool down between the intervals is bad for the starter and can cause burnout.
Repeated attempts to restart a car engine
Making several consecutive attempts to start the car engine can lead to burning out of the starter.
This can happen during cold weather or in the case of low battery voltage when the magnetic switch fails to hold causing chatter of the solenoid, repeatedly switching on and off the power to the motor heating up and burning the starter.
You may also want to read: Why your car battery voltage drops overnight
Stuck starter relay (if the car has one) can also burn out the starter motor
The car may also have a failed relay with welded contacts that continuously supply power to the starter motor causing burnout.
In other cases, a bad or damaged magnetic switch can get stuck and fail to disconnect power from the starter motor leading to heat buildup and burning out of the starter.
You may also want to read: Why your car relay may go bad
Using starters of a lower power rating
Using a replacement starter with a lower power rating than the car engine requires (under-sizing the starter) can lead to the car starter burning out. For example, when you use a 1kW starter in a car that requires a 2kW starter.
The excessive power demands of the car on the starter will cause the starter to burn out.
3. Symptoms of a Burntout Car Starter
You can tell that you have a burnout car starter when:
- The engine fails to crank because of a defective starter yet the car battery is sufficiently charged and all battery connections are clean and make firm contact, and
the car starter receives sufficient voltage of at least 9V for a 12V battery system when measured across the starter terminals while starting the car
- There is a burning smell, in some cases smoke coming from the car starter
- The insulation or label on the starter body melts
You can also tell by opening and inspecting the starter. A burnout starter usually has
- burnt out commutator
- discolored terminals from the excessive heat buildup in the starter
4. Tests to Confirm a Burntout Car Starter
Check that there is sufficient battery voltage at the starter supply terminals.
Next follow your starter manual guidelines to conduct both voltage drop and current draw tests on the starter using a digital multimeter.
Excessive current draws and excessive voltage drops in the starter following both current draw and voltage drop tests likely point to a problem with the starter which may be caused by a burnout.
5. How you Can avoid your Car Starter from Burning out
To reduce the chances of a car starter burning out:
Do not keep the ignition key in the start position for more than 10 seconds. Release it and allow it to cool for 60 seconds before turning the ignition to start again. This allows the heat generated from the current flowing through the windings to dissipate
Always fix the underlying causes of car starter failure before replacing the car starter. This could be a user behavior issue such as starting the car repeatedly during cold weather or component failure, such as a starter relay.
There are cases where a failed starter relay with welded contacts that continues to draw current from the battery through the starter motor causes it to burn out. If not fixed, it is possible to burn out multiple starter replacements!
Always replace with a starter with the recommended power rating for your car’s engine
6. Can you Fix a Burntout Car starter?
If the car starter is burnt out, burned out windings, armature it is best to replace it with a new starter for your car engine to work reliably for a long time.
With a burnt-out car starter, your engine will not be able to crank and start.
You may be able to recognize a burnt-out starter when the car engine fails to crank and you have a burning smell, sometimes smoke from the starter or burnt insulation on the starter body.
You will likely see burnt commutator and windings when you open up the starter.
You can reduce the chances of the car starter burning out when you avoid keeping the key in the start position for a long time, allowing it time to cool between attempts to start.