3 Step Starter Motor Testing Guide

Starter Motor Problems?

If you car won’t start or struggles to fire up, this could indicate starter motor problems. There are three basics checks that will assist your diagnosis. And, if your vehicle passes the following 3-point test, your starter motor might not be faulty after all.

Starter motor problems can cause the obvious side effect of an engine that wont start or struggles to start. Simply follow our three step starter motor testing procedure in a methodical order to ensure fault detection as early as possible.

Step 1: Check the Battery

Make sure your battery is well charged. If you have any doubts, try jump starting the engine. If your engine starts using the jump leads, you may well have a flat battery rather than a faulty starter motor. In this case get a qualified mechanic to test your battery.
Battery Test: If the car started with jump leads test your battery

Step 2: Inspect the Starter Motor Wiring

If the engine won’t start using jump leads, the next step will be to check the wiring to the starter motor. To do this it is best to re-earth the engine by connecting a single jump lead between the battery negative terminal and the engine block.
**Ensure that your vehicle is a negative earth system** - this will be evident if the negative battery terminal has an earth strap connected to the bodywork or engine block.
After successfully re-earthing the starter motor try and start the engine. If this is successful it indicates a problem with the engine earth strap(s). In this case, check the wiring and connections of all earth straps and retest.

Step 3: Check the Thick Battery Positive Lead

If your engine still fails to start you need to check that the thick battery positive lead from your battery positive terminal is not loose, damaged or corroded. If you suspect a damaged battery lead then remove and clean, tighten or replace.

Ignition Switch Failure

In some rare cases ignition switch failure can cause a starter motor to fail.

Need a Replacement Starter Motor?

If our 3 step starter motor testing proved inconclusive, you may need a replacement starter motor. As always we recommend seeking expert advice. Give us a call today for guidance on 0845 564 2681. Alternatively visit the starter motor section of our store to find a replacement today.

Our testing guides should be used for guidance only. We advise you to seek expert advice from a qualified mechanic if you suspect a faulty engine part. Before attempting work on your car, firstly read our Safety Guide.