How to tackle faulty ignition start switches
How to tackle faulty ignition start switches

How to tackle faulty ignition start switches

Faulty ignition starter switches are common on Vauxhall/Opel models as well as many other makes of vehicle. A faulty ignition start switch results in a permanent electrical feed to the starter solenoid “s” terminal. This problem can result in the starter motor being “held in mesh” whilst the engine is running (known as ‘over-run’).

There is a simple three-stage process for checking if the start switch has failed. Firstly, check the armature shaft and if the drive pinion is showing evidence of heat damage or heat discolouration. Next, does the starter motor or solenoid smell burnt? If it does, there’s an issue. Is there any pinion damage or ring gear damage? Again, this is a tell-tale sign that the starter switch has failed or is faulty and needs to be replaced.

Next, you have to tackle any electrical issue on the control circuit. However, there is a very quick and easy way to do this and all you need is a 12V test lamp or voltmeter.

Roll with it

Rolling Components or “RollCo” is a leading supplier of high quality alternators, ignitions and starter motors to the aftermarket. When replacing components, make sure you choose an aftermarket manufacturer, such as RollCo, which supplies OE standard products that give you and your customer peace of mind.

faulty ignition start switches

How to check the control circuit – 3 easy steps

  1. Remove the lead from the solenoid switch terminal and connect a 12V test lamp or voltmeter on the wire, switch to crank position and the lamp will light.
  2. Release the key.
  3. If the lamp stays on, replace the switch.

It’s a simple test, but will ensure your diagnosis is correct!


For more details on RollCo’s product range visit

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