SID = 'Rear light failure' / replacement

[TomPaine]

Hi all. SID [MY04 9-5 estate] has been saying 'Rear light failure' for a couple of days and, knowing that it senses resistance in a failing bulb rather than simply reporting a failed one, I've been keeping an eye out, and sure enough the far right of the rear four is on and off. [It comes on again with a tap, but I know that's not a lasting fix...]

I was simply wondering:

- are they easy to replace [which would spare hassle of dealer visit]

- are there any partic ones to buy, and

- should one replace in pairs, i.e. also replace the left brake light [or even all four, i.e. the standard inner lights as well as outer brake lights]?

Many thanks for any counsel.

[sgould]

I’m have a different set-up on the 2006 estate, so I can’t advise on how. But the system works by comparing resistance between left and right. So a brand new bulb and a working, but nearly dead one on the other side may show enough difference to trigger the warning.

[collywobble]

OSRAM make 'Ultralife' 21W and 21/5W bulbs......supposed to give longer life - £4.19 & £4.39 a pair from Euro Car Parts...I recently replaced one of mine - just follow the instructions in the owners manual.

[TomPaine]

Thank you gents. Those bulbs ordered and handbook at the ready. I assume you'd suggest that I replace the lot?

[sgould]

Probably the best thing to do.

Be careful when you insert the twin filament bulbs.  It’s very easy to push them in a bit too far.  Then they turn round further than they should and the lighting and brake circuits get cross connected.  That causes all sorts of strange electrical behaviour..