Front side light issue – DB9

[RJ5560]

Hi all,

I had been enjoying an error free 5 weeks on my car (normally TPMS throws at least a fortnightly error to keep me from complacency), when the front passenger side light (blue bulb) stopped working (no error on the dash though). Assuming the bulb had gone I booked it in to get it replaced just prior to the MOT – and it starts working again (and passed the MOT). Now when I drive the car, it randomly works or doesn’t (I have used the car maybe 10 times.

The dipped beam, main beam and indicators on that side are all fine and the battery is on a conditioner when it is parked. I don’t have any moisture inside the light unit.

Any ideas would be appreciated,

Thanks!

[telum01]

Check the connections going to/from the headlight. I had a DB9 come through that had a VERY loose connection - the cable was so loose it kept falling. Just one possibility, though.

[8Tech]

The filament could be damaged and breaking and remaking contact randomly through vibration.
This is one of the most common faults on modern cars that have a lamp checking system showing a bulb failure in a bulb that is quite obviously working when checked.
The lamp checking circuit sees an unexpected electrical resistance and assumes a failed bulb.
Just replace the bulb.

[mrpseudonym]

I had this issue a couple of times, and initially suspected the bulb so replaced it, but problem was the copper contacts in the lamp housing needed to be ‘persuaded’ to be a bit tighter. Just bent them slightly with a screwdriver back towards the centre of the housing and haven’t seen the problem again. thank goodness because access is a pain.

Edited to add: use the opportunity while you have them out to replace the blue globes with T10 Wedge LEDs that are CANBus Compatible..sooo much better

Edited by mrpseudonym on Tuesday 21st November 08:57

[RJ5560]

That's great - thanks guys. I was considering the LED options for the side lights so that is very useful. RJ5560

[shuzzy]

The biggest problem with the sidelight bulbs is access. I believe its a wheel arch liner off, airbox out job access this area of the headlight!