Dipped headlamps

The dipped beam headlamps on my 2008 Ford Focus 1.8 TDCI estate won’t switch on. As you know, the headlamps go off when the ignition is turned off, as is usual with Ford vehicles. All other lights work normally – fog-lamps, parking lights, etc. The separate headlamps for main beam work normally and I can hear a clicking sound like a relay operating on the passenger side fuseboard when I operate the dipswitch to put on main beam. However, when the main beam is on and I turn off the main light switch, when I turn it back on, the main beam doesn’t work until I operate the dipswitch again. This may be to stop the driver switching on the main beam lamps just by turning on the light switch, but I cannot be sure. I believe I have checked all the relevant fuses, but drawn a blank. I cannot believe that both fuses for the left and right dipped headlamp beams failed together!

I am aware that this car has a Canbus system and that there is Gem control unit somewhere, but isn’t there a plug-in relay involved which controls the light operation when the ignition switch is operated? Or is it a part of the Gem unit? The unit looks complicated and expensive, and Haynes says a replacement must be programmed in by a Ford dealer. Frank Bailey

Before I had a chance to reply to Frank's question, I received an update.

I should have started by checking the obvious culprits: the bulbs. Amazingly, both filaments were blown, probably by a voltage surge. They were switched before operating the starter, so I will remember not to do that in future. Seems simple, but in all the years I have owned motor vehicles, this is a first for me.

While I’m on the subject, do you know of any way one can fit an offside reversing lamp to this vehicle? There is only one reversing light provided in the nearside light cluster, with the space in the offside rear light cluster occupied by the highintensity fog-lamp. Maybe it would be easier to fit a separate high intensity fog-lamp so that the second reverse lamp could be fitted in the space vacated. It’s so annoying having just the one reversing light on the nearside, but I suppose it was fitted that way as most vehicles produced are left-hand drive. Frank Bailey

It is quite common for two bulbs to fail at the same time. It can also be the case that one bulb fails ahead of the second and, for a short time, the vehicle will drive with only one headlamp working. This will normally supply a modicum of light on the road ahead and, depending on the weather and other factors, may not always be noticeable. When the second bulb goes, the situation becomes apparent.

The reversing light on the Focus is on the nearside on both left-hand drive and right-hand drive vehicles. This is because the fog-lamp which uses that location in the lens on the opposite side always has to be fitted to the offside to conform to legislation. A second reversing light is something that many Focus owners prefer and

fordownersclub.com has published a very good step-by-step guide to carrying out this modification at this web address: http://bit.ly/2mecoe3