No end of problems the past few days.

12v lighter socket didnt work so I replaced the fuse, Within 5 hours of doing that the battery was dead. Removed the fuse and charged the battery last night.

Seemed fine thismorning when driving to work. After work the battery had just enough energy to start it. Took it streight to Ford, who refused to test the battery/alternator as I asked because the technician was going home (4.45pm seemed a funny time but hey)

Then got home to be told when I brake the right rear lights go off (side lights and brake) but left stay on. (this has only started since I removed and recharged the battery last night)

Seems endless troubles at the moment.

Any ideas whats causing the rear side light to go off when I brake?

Any help would be much appreciated.

Just looking at the rear lights, looks like the rear sidelight and brake light is run on the same bulb.. is this correct? If so what would cause the side light to go out when the brake is applied?

Its either an electrical fault or the battery doesnt have any juice a failed battery can cause all sorts of electrical gremlins any garage will do a free test doesnt have to be fords

Hi, James

your rear bulb as two elements, so it is one bulb doing two jobs, if going off when you brake can be caused by a bad earth point, when you charged your battery, and refitted it, was the earth terminal tight, plus look at the rear light for a bad earth, this is a good place to start, also have a look at the 12volt lighter socket wiring for any short's..as this could make the battery go flat, also make sure that the right fuse is fitted.

as above, the bulb is a dual filament bulb.

make sure someone hasn't changed it for a single filament bulb.

as above, the bulb is a dual filament bulb.

make sure someone hasn't changed it for a single filament bulb.

It was fine the day before I had the issues with the flat battery so it wont be that.

It was fine the day before I had the issues with the flat battery so it wont be that.

By resolving the issue with the 12v socket, any electrical circuit that may have stopped there could now be making it as far as something using more juice

It's a long shot, but at least quick and easy to check

As already stated your rear light problem is most likely to be a bad earth on the affected bulb. What happens is that the current flows through the rear light filament, then through the brake light filament, then back via the brake light wiring and through the other-side brake light to earth. Although the brake filaments have a lower resistance than the rears there will be some voltage drop so this will normally show up as the rear light being dimmer on the affected side. When you brake the bulb has 12V on both filaments so with no earth there is no voltage difference across them hence no current. This doesn't necessarily happen just with dual-filament bulbs, it will happen with any lamp assembly where there is a shared earth.

The fact this appears to have happened since you had to charge the battery is probably just coincidence, someone just happened to notice it and tell you about it at the same time.

Yes i will go with Mike on this one, that the light problem was not noticed, this could also have a bearing on the battery going flat. give the car a good looking over, it will be the only way to get to the bottom of this problem.

Cars sorted, everything happening at once was just one big coincidence.

One of the filaments in the bulb was shorting on the other causing the issue with the side/brake light, new bulb sorted that.

Checked the alternator output which was fine. New battery it was and everything is fine.

The 12v lighter socket just needed the fuse putting back in, theres nothing else other than the fuse in the socket system so that too was just a coincidence that I put a new fuse in several hours before the battery died.

Big releif as I hate electrics which was my main fear on updating to a new'er car

Glad your car is sorted.Nothing worse than a car with problems that you don't know how to fix or when it can be fixed. :)

Glad your car is sorted.Nothing worse than a car with problems that you don't know how to fix or when it can be fixed. :)

Indeed, especially when you rely on it every day and have put your every penny's earnings into saving for it

Hi James, I'm glad to hear you got it sorted so simply, and thanks for reporting back. It's always nice to know whether we've been any help. I've never known a twin-filament bulb do that before but at least it was an easy fix.

Nice one James. :D

Thanks, Cant beleive that everything happening in 1 day was a coincidence!

Glad it's fixed ... what a set of symptoms!