brake light problem

[ajmacintosh]

Upon checking the lights before moving off our pitch yesterday, my Wife noticed that one of the brake lights was not working on the back of our caravan. I checked the brake lights on the car and all was well so I reached for my toolbox and spare bulbs and proceeded to change what I thought must be a faulty bulb.

Having chaged the bulb with 3 new spares, this did not solve the problem. I then checked the connections on the plug and socket but they seemed to be fine. Is there a fuse I can check or has anyone any ideas on what I can check?

Thanks in advance

Andrew

 

[Lutz]

Normally, all brake lights are served by the same fuse, so two obvious possible causes spring to mind. Either there is a poor connection somewhere between the brake lights or the earth connection on the side that is affected is poor. In the latter case, the sidelights and/or the indicators would also not be working properly.

 

[ajmacintosh]

Thanks Lutz, the side lights and indicators etc are all working fine. So it could be a bad earth?

 

[Lutz]

I would assume that sidelights, brake lights and indicators all use the same earth connection so either there is some local corrosion within the lamp unit in the area of the brake light terminals or you need to check whether the wire carrying the brake light current is actually alive or not.

 

[WatsonJohnG]

If its working on one side you need to check for continuity between the +ve terminals on the 2 brake lights

If there is no continuity then look for a connector thats pulled out/bad connection etc