Strange broken bulb warning behavior

[Myrri]

I'm stumped by the broken bulb warning in my Vectra. I just recently got the car, had the light on. Just thought it was because of corroded contacts somewhere since all the lights worked just fine. So i changed every single bulb in the rear, cleaned the contacts, checked the contacts in the front, and the light is still on.
I do have LEDs on low and high beams, but they are installed with relays and resistors (the light was on even before installing them). I also tested with new halogen bulbs, didn't help.
The warning light goes away when i activate high beams, and when i turn them off it comes right back on. Same thing happens with my sister's Vectra. Both facelift, if that matters. Both of the cars don't for some reason tell what bulb they think is broken, so i don't have any idea where to start troubleshooting.
Has any of you had the same problem before, and how (if at all) did you fix it?

[northpole]

Do you both have front foglights? If the answer is yes, check them for corroded connectors... I used to have that problem and in the end I replaced my foglight units. And I used to clean the UEC to get rid of the warning light but it would always come back.

The corrosion caused to much resistance, and in such a way that at something I could clearly see it burning the plus to the bulb in the housing. After I replaced them the warning light works as it should.


Ps you need to scan the car for an error code as this gets logged and it will tell you what light is causing it to pop on.

[Big Dave]

Double check the rear bulbs.

They should all be single filament 21w 12v bulbs.

If the indicator lenses are clear, then you'll need orange bulbs that have offset pins.

There are 2 tail light bulbs on each side of the car. The upper one is also the brake light. Should the upper bulb fail, the lower bulb takes over the role of tail / brake light.

Rear light positions (from the top down)

Indicators
Tail & brake lights
Tail lights (which then becomes a brake light as well should the original tail/brake light fail)
Fog light (drivers side only - UK)
Reverse lights.

[Myrri]

I checked the fog light contacts and indeed found some corrosion, so i cleaned them but that didn't help. Also double checked rear lights, they are fine.
I unfortunately only have a generic OBD2 scanner available for me so that's not going to tell me anything useful.

[northpole]

Pull the headlight fuses out of the UEC... f8 and f9 put new ones in than turn the lights on... as when I got my car I had to replace most fuses although they were fine they all had to much resistance. Once replaced my car stopped giving me false light warnings.

I also had this after I replaced the foglights. So it might be the same with yours. Mind you my car is from 2003. And the only fuses I haven't replaced are the big heavy fuses, all the mini fuses have been replaced.

[Myrri]

Tried replacing all the small fuses in the UEC, cleaning the contacts with contact cleaner and replacing the foglight bulbs. Light is still on, except when high beams are activated.

[northpole]

well in that case i would get the car read with a vauxhall specific reader as it might be something as simple as to much corrosion on a bulb or the bulb holder... I know it can be a pita if you can't find it by just looking at it... usually it is the rear light clusters that cause it and usually on the brake light bulbs.

but it could be that corrosion you found on the foglight as the bulb-check will check all the bulbs, regardless if they are on or off, and corrosion can cause to much resistance.

[Myrri]

well in that case i would get the car read with a vauxhall specific reader.

I'll try to do that, thanks for the help