Rear light out but works again with headlights

[Willcbrbikeboy]

Hi, I have a astra gtc biturbo with standard rear lights. With the drls on the left side rear had the bulb working but the offside rear is off. If I switch the headlights on then both bulbs work as they should. Anything causing the rear not to work? On the front I have led drls and installed a hid kit for the headlights all of which work well..

[Rusty2009]

On the 5-door when DRL's are on it's only DRL's that are on no rear lights on at all, I would of thought it should be the same for the GTC.

[marktourino]

My DRL's are the only lights on when driving daylight conditions, my rear lights turn on when the auto lights settings kick in or alternatively if I manually turn on the lights, can't imagine any difference in the wiring set up, mine's on a 14 plate with LED rear lights.

[Willcbrbikeboy]

Well from your replies sounds like 1 bulb is getting power sent to it, v strange. I wonder if the front set up has anything to do with it then.... Maybe due to the drls on the front being led and using less power...

[niteram]

As said above, usually only the front drls come on, no rear lights
the normal drl bulbs are twin filament (one for drl, one for sidelight)
if you have a faulty bulb fitted, it's possible that it is backfeeding power into the sidelight circuit - which will make the rear bulb light up.
(its a bit like when a bad earth makes all the rear lights flash with the indicators)

If it was mine I'd try the original drl bulbs as a help to diagnosis

[Willcbrbikeboy]

Thanks for the help guys, I don't know what made me think the rear lights were on all the time. I will try the original bulbs back in the drl and see what happens  in these dark mornings all the bulbs are working correctly so I will have to change them next weekend now. Cheers guys  

[vocky]

normally issues like that are caused by the wrong bulb or the bulb incorrectly fitted