Turned the ignition switch only to be met with silence?
Frustrated that your engine won’t crank?
Sounds like your starter solenoid is faulty. Unfortunately, you won’t be going anywhere until you replace it.
Not sure where to start?
Don’t worry — we’ll get your car revving into life with our breakdown of the starter solenoid replacement steps, diagnostic procedure, and associated costs.
This Article Contains:
- How to Diagnose a Faulty Starter Solenoid
- How to Replace a Starter Solenoid Step-By-Step
- What Causes a Bad Starter Solenoid?
- 4 FAQs on Starter Solenoids
How to Diagnose a Faulty Starter Solenoid
Diagnosing and replacing a starter solenoid requires specialized skills and knowledge, so it’s best to have a mechanic handle it.
Here’s how they would test it:
- Check for symptoms: A clicking sound when turning the ignition switch, no response when turning the key, a lack of engine cranking, and inconsistent starting all indicate a bad starter solenoid.
- Use an OBD II scanner: They’ll connect the scanner to read any problem codes. A P0615 (“Starter motor relay-circuit malfunction”) could indicate a faulty starter solenoid.
- Test the solenoid charge: They’ll measure the voltage at the solenoid terminals using a multimeter. When turning on the ignition, the voltage reading should not drop more than 0.5 volts from the initial battery reading (12.6 volts when the car is off).
- Inspect the solenoid connections: Corroded terminals and loose wiring may interfere with the current transfer from the battery.
Once the mechanic determines your starter solenoid is beyond repair, they’ll begin replacing it. Let’s look at the steps involved.
How to Replace a Starter Solenoid Step-By-Step
Here’s what the starter solenoid replacement involves:
Note: In many modern cars, the solenoid integrates with the starter. In this case, you’ll need to replace the entire starter assembly. Here, we’ll cover the steps for replacing a starter solenoid that’s separate from the starter motor.
Step 1: Locate the Starter Solenoid
In some modern cars, the solenoid attaches to the starter motor below the car at the bell housing where the engine and transmission connect. The solenoid is higher up for older vehicles and attaches to the firewall.
To locate it, a mechanic may trace the positive cable from the battery to where it connects to the solenoid in the engine compartment.
Step 2: Jack Up the Vehicle
In some cases, accessing the solenoid requires jacking up the vehicle. The mechanic will position the jack under the jack point at the front of the vehicle and engage it as necessary.
Step 3: Disconnect the Battery and Wiring
They’ll loosen the bolt on the battery’s negative terminal, slide it off the terminal post, and then do the same for the positive terminal.
To keep track of the wires, the mechanic will mark which wires correspond to each solenoid terminal before unclipping them. This helps avoid connecting the wrong wires to each terminal, which results in a blown fuse.
Step 4: Remove the Old Solenoid
The mechanic will unscrew each mounting bolt, attaching the old solenoid to the starter motor.
In some cases, they’ll need to remove the starter motor (and starter housing) to access the solenoid. This requires unscrewing the starter mounting bolts that secure it to the bell housing.
Once they remove each mounting bolt, they’ll separate the solenoid from the starter motor.
Step 5: Connect the New Starter Solenoid
First, they’ll confirm that the new solenoid fits in the engine compartment, as starter solenoids have different designs. Then, they’ll install the new solenoid on the starter motor and tighten each bolt.
If removed earlier, they’ll reinstall the starter motor by placing it back in the starter housing and tightening the starter mounting bolts to secure it.
Step 6: Reconnect the Wiring and Battery
The mechanic will reattach each wire to the correct solenoid terminal according to the markings. They’ll then reconnect the battery, starting with the positive terminal.
Step 7: Lower the Vehicle and Test the Solenoid
They’ll lower the vehicle into position and turn the ignition key to ensure the new starter solenoid can start the car.
You’ve mastered the replacement process, but now you might be asking yourself: what led to a failing starter solenoid in the first place?
Read on to find out.
What Causes a Bad Starter Solenoid?
Several issues result in a bad starter solenoid, including:
- Faulty wiring: Loose connections or an improperly connected solenoid terminal can disrupt the current flow. This can lead to inadequate power supply or short circuits, causing a solenoid problem.
- Excessive heat: High currents flowing through the solenoid (often due to prolonged engine cranking) can generate excessive heat, which may damage the internal components.
- Moisture: Moisture entering the solenoid housing can lead to corrosion of electrical parts within the starter circuit, reducing conductivity and efficiency.
Still have some questions about the starter solenoid?
Read on to find the answers.
4 FAQs on Starter Solenoids
Here’s everything else you need to know:
1. How Much Does Replacing an Old Starter Solenoid Cost?
It’ll cost between $450 and $610 (including labor) to replace an old starter solenoid. The final cost depends on your location, vehicle model and make, taxes, as well as insurance coverage.
The cost also depends on whether you purchase an OEM starter solenoid, as these tend to be more expensive. If you can find the right type for your vehicle, you might be able to get a rebuilt starter solenoid. However, rebuilds aren’t always reliable and may not last as long.
2. How Does a Starter Solenoid Work?
The starter solenoid consists of several parts, including the solenoid housing, terminals, starter relay, plunger, return spring, contact plate, and solenoid cap.
When you turn the ignition key, an electrical current moves through the control circuit from the battery to the solenoid, creating a magnetic field that engages the plunger inside the solenoid.
Once the magnetic field causes this plunger to close the gap in the starter circuit, current enters the motor and engages the starter gear (pinion gear). As the starter gear turns, it engages the ring gear on the engine’s flywheel, which cranks the engine and starts the combustion cycle.
3. Can a Starter Work with a Bad Solenoid?
A starter will experience issues when there’s a malfunctioning starter solenoid, but it may still work under certain conditions.
For instance, if the connection is faulty, you may still be able to start the engine by repeatedly trying to engage the ignition system. However, this isn’t advisable as it could lead to overheating and damage to other car parts, which you may need to repair.
4. How to Prevent Starter Solenoid Issues
Here are some car maintenance tips to prevent a failing starter solenoid and costly auto repair:
- Inspect and clean each starter terminal: Use a brush and baking soda to remove oxidation or debris buildup.
- Check the wiring: Ensure the wiring in the starting system connecting the solenoid to the battery is free of wear and tear. You should also check the wiring in the ignition system to ensure it’s carrying current to the spark plugs.
- Avoid excessive heat exposure: Cranking the engine excessively may overheat the system. Also, ensure your vehicle’s cooling system is functioning optimally by conducting a pressure test for leaks.
- Drive your vehicle regularly: Driving your car charges the battery, ensuring it can provide the solenoid with sufficient voltage.
Crank Your Vehicle to Life with AutoNation Mobile Service
The starter solenoid is a crucial part of the starting system as it transfers current from the battery to the starter motor. Without it, you won’t be able to start your vehicle properly.
Stuck at home, unable to get your car to a mechanic?
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Contact us for any auto repair, replacement, or car maintenance procedures.