Rick's Free Auto Repair Advice

Starter clicks once but won’t crank the engine — The Most Common Causes

Starter clicks once but won’t crank your engine — The Most Common Causes

If you turn the key and the starter clicks once but won’t crank the engine, the cause can be four things. This article shows you how to diagnose and fix the problem.

Possible causes of single click from starter

1) A dead battery can cause a single click from the starter

A discharged battery can generate enough power to turn on dash lights, but not enough to operate the starter motor. In that case, the single click when trying to start the engine is caused by the solenoid pull-in and hold-in coils are working. But the low battery power isn’t enough to power the starter.

2) Corroded battery terminals can also cause a single click from the starter

Just like the dead battery symptoms above, if the battery terminals are corroded, the high electrical resistance prevents the starter from getting enough power to crank the engine.

4) Bad starter relay in the fuse box

Some carmakers use a small relay located in the fuse box to switch power to the starter solenoid. If the contacts in the fuse box starter relay are pitted or burned, the single click when trying to start the engine can be the relay trying to switch power but failing.

5) Bad starter motor

If the brushes, windings or armature are damaged/worn, the solenoid will make a single click sound but the starter won’t crank the engine.

How to diagnose a single click when trying to start the engine

Check the car battery state of charge

This is best done with a multimeter. A fully charged battery is 12.6 volts. If the battery reads less than 12.2 volts, it is discharged. If you don’t have a multimeter, try this:

  1. Turn on the dome light.
  2. Turn off ALL other electrical accessories; headlights, blower, rear defogger, and heated seats.
  3. Turn the key to START while watching the dome light. If the dome light dims way down, your battery is discharged. It only takes a few watts of power to run the dome light. If your battery can’t provide that little bit of power while trying to operate the starter, it’s most likely a dead battery. But there are more things you can try before you give up.

A car battery works by chemical reaction. The reaction slows when the battery is cold. So you want to warm it up. How? Simple. Repeat Step 3 several more times. Each time you put a load on the battery you’re creating heat. If it still doesn’t crank after the 6th or 7th try, it’s toast.

Test your car battery with a battery tester

See this article on how to test your car battery.

Check the car battery connections

Battery terminals must make good contact to carry the 100-200 amps needed to operate the starter. You can’t always tell if the terminals are corroded visually. I know you don’t have tools with you to clean the terminals, but here’s a trick. You need to move them or at least vibrate them to get a better connection

Smack the side of the positive and negative battery terminals with the heel of your shoe. Don’t hit straight down on the terminal; the goal is to force them to rotate slightly. I’m not kidding, this works?

If you’re at home and have tools to clean the battery terminals, click here for the procedure

If you’re sure the battery is dead and you want to replace it, click here for step by step car battery replacement instructions

Swap the starter relay in the fuse box

If you hear a faint clicking sound coming from the small starter relay in the fuse box but the starter won’t crank, you can try swapping in a different relay. The starter solenoid’s job is to connect the large gauge battery cable to the starter so 400 amps can push the starter drive into the flywheel and rotate the engine. Carmakers often use a small relay in the fuse box to switch power to the starter solenoid. Sometimes the contacts pitt and won’t transfer power. That’s when you try swapping in a different relay. Here’s how.

Here’s a diagram of a typical starting system that uses a fuse box relay.

1) Locate the relay in the fuse box
2) Find a different relay that looks just like the starter relay
3) Yank the starter relay straight out (rocking it side to side as you pull will help)
4) Substitute the other relay and try starting the engine. If it works, the relay is bad. Find a replacement at any auto parts store.

starter system wiring diagram

If everything passes but you still get a single click when trying to start the engine, chances are the starter motor is worn out

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat



Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN