If you haven't got a multi-meter it might be a cheaper option to buy a cheap one (about six quid) than replacing bulb-holders etc. There is also a cheap LED voltage tester that you can get from car-parts shops - it's just a plastic stick with a line of LEDs. Clip the black lead to eath and the red probe to your wiring terminals and the LEDs light up to show the voltage. I have found that the quality of Vauxhall wiring is suspect, with the use of dis-similar metals in bulb holders which causes connection problems.

Failing the availability of a test-meter, Just try running a wire from the earth terminal of the faulty bulb holder directly to a clean (not painted) bolt head or nut on the bodywork, and then a wire from the live terminal of the working bulb to the 'live' terminal of the non-working bulb and see which one lights the bulb.

If the other lamps in the cluster (indicator, reversing light etc.) are working, then the earth connection must be OK.

Edited by MrEckerslikefromRamsbottom on 03/07/2014 at 17:58