Every time you turn the key, you expect the engine to start. When the engine doesn’t start, there is a disruption in the current between the starter solenoid and the starter motor. However, a bad starter relay may be the issue when the car doesn’t start.
Here we look at the signs of a bad starter and three ways to troubleshoot the starter to see if it is faulty.
Symptoms of a Bad Starter Relay
- Rapid clicks from the starter relay
When you turn the key and no engine starts but you hear the clicking, the starter is trying to open and close the circuits and has failed. The result is the clicking you hear.
What’s happening? The starter is worn out and needs replacing.
- Random engine start failure
A good starter relay transmits the current to the starter every time the key turns. However, things like dirt, faulty wires, the engine running hot, and grease on connections can affect the start relay and result in it starting the car sometimes and not starting others.
- Starter relay stays on after the engine starts
The starter relay staying on is the opposite of the car not starting.
Here, the starter relay doesn’t close the electrical circuit, and the starter motor continues to run after the engine starts up. The starter motor will sometimes run when you take the key out of the ignition.
An unclosed circuit can lead to flywheel damage and burn up the starter that needs to be looked at immediately.
- Car won’t start
As you turn the ignition key, electrical energy from the battery is released.
The engine starts as the starter motor prompts it. The bridge between the starter motor and your engine is the starter relay.
The starter relay keeps the starter motor’s stronger current from burning out the ignition switch, which needs less power.
The electrical current never makes it from the battery to the starter motor when the starter is bad. As you turn the key, you get a clicking noise but no engine start-up. This issue needs to be taken care of immediately!
- Oil soaks the starter
The starter is positioned at the bottom of the engine and can get soaked by car fluids. When oil soaks the starter, it will shorten the starter’s life.
You will need to replace the starter and fix the leak to ensure the car will start and prevent this from happening again.
- Starter solenoid isn’t getting the signal
A faulty relay doesn’t send the current to the starter solenoid. So no signal means the car won’t start.
Fixing a Bad Start Relay
Method 1: Using jumper cables
- Wire brush
- Baking soda and water
- Fully charged battery
- Jumper cables
Step 1: Safely park your car
Park on flat ground with the car in park or neutral; this will keep the vehicle from moving while you work.
Step 2: Find charged battery and jumper cables
Gather your jumper cables and a fully charged battery. You need to test the battery to ensure it is not the problem.
Monitor the placement of the jumper cables on the battery terminals while you are testing.
Step 3: Check the battery terminals and starter
Check the battery terminals for debris, dirt, oil, and rust (the terminals need to be clean). Next, remove the negative battery cable (as you disconnect the cables, do not bump them together!), then remove the positive battery cable.
Next, make a paste with the water and baking soda apply it to the terminals with a damp toothbrush, scrubbing off any rust and dirt.
If the starter terminals are dirty or corroded, clean them too. Then, if possible, you can disconnect the battery cables.
Step 4: Check the route from cables to starter solenoid then to the starter relay
Going from the starter selonoid, follow the cable’s path to the starter relay.
Note that there are four terminals on the starter relay plus two small wires that turn on the relay and go to the key switch circuit. The larger two wires transmit the battery voltage from the battery to the starter.
It is always good to mark your wires before you remove them to reconnect them properly. After the wires are marked, remove the starter relay wires.
Place a jumper cable to the chassis ground and the second jumper cable to terminal # 86.
Step 5: Place jumper cable on the positive battery terminal
Place the jumper cable on the positive battery terminal (once the starter is disconnected, it is safe to leave the jumper cable attached). Using a voltmeter to check the voltage between terminals #30 and # 87.
You want a resistance of one ohm or less. A resistance of above one ohm means the starter relay needs replacing.
Method 2: Using the test light
- Small paperclip
- Light tester
Find the small wire and thick cable on the starter solenoid with the car parked and the engine off. Using a small paperclip, straighten on end and place the small wire connector safely in the back of the starter-S terminal.
The paper clip shouldn’t move (you don’t want it to hit any metal). It will make getting to the connection a bit easier. Have someone start the car while you test the paperclip with the test light.
If the starter clicks and the light is bright, you need to replace the starter; your circuit is still good.
Method 3: Check the voltage at the solenoid starter terminal
To test the amount of voltage to the solenoid starter, locate the solenoid’s feed terminal and touch the bare metal on the motor with the negative lead of the voltmeter.
The voltage should drop no more than half a volt, so if it was 11 volts, it should only drop to 10.5 volts.
A reading above 10.5 means the starter is good, and the problem is elsewhere. If your reading loses half a volt or more, your starter will need replacing.