Tips to fault find a 3rd brake light?

[Leigh]

This is in advance of me hopefully having a look tommorow..
At some point during the last week or so my 3rd brake light has ceased working, but I only noticed a couple of nights ago when backing up to the garage wall.

It's a Hella unit (I think..) that was already fitted when I bought the car 2nd hand 1.5 years ago, I know the wiring is routed under the trim on the underneath of the boot lid, so I will attempt to check the obvious tommorow (wires fallen off etc), but I was wondering if anyone knows what the supply to it is likely to be , 12V ? 5V ?
I haven't looked closely enought to tell if it's using LED's or filaments, but it's fairly bright when active.

I'll try with a multimeter to see if there is anything at the point where it's connected (assuming I can see/reach it), my other thought was that if it's a low enough voltage requirement I could try power it off a battery just to see if the light works.

Any tips for when I look would be great,
thanks,
Leigh

[Fraz]

Hi these things are basic enough...all they have is a live feed which will be tapped into the brake light live feed somewhere (usually at rear of light cluster) and an earth wire ....obvious thing to check is the bulb (if its a bulb and not LED's

the voltage will be 12v

if the light opens it will be more likely to be one that uses a bulb as led ones are usually a sealed unit

[Leigh]

Cheers Fraz.

I've never taken it off or looked in any great detail at it since getting the car since it's always worked fine up until now. I did expect it to be 12V, especially if it turns out to be a bulb and not LED's, a 5V brake light blub wouldn't do much!

I'll be looking either later on tonight before I go out on the p*ss, or tommorow (more likely tommorow..)

[Leigh]

Well that was easy for a change [img]/biggrin.gif[/img]

Found the wire connected to the brake lights via a scothlock, and the clip was open, closed it, tried the brakes, lights working again.