So i bought all new bulbs for the exterior. Installed em all today and found that the left rear parking light works but not when i press the brake, goes dark. Only one of the double inner components of the bulb light up. Tried other bulbs with same outcome. Checked fuses and all good. Wiring problem perhaps?

 

ANYONE?!?!

 

The brake lightbulbs are usually dual filament bulbs. Meaning, they have two filaments.

But wait, there's more!!

The first filament lights with the parking lights and the second lights when the brake pedal is depressed.
More than likely, you have a bad filament. If not, you have bad wiring. You can follow the wiring and look for the short or take it to a savvy car guy to fix it for you.

 

yup, i know its a double .. .chose wrong word (component=filament) .. its gotta be wiring since ive tried multiple bulbs. Now, follow it how far, im not tearing the entire car apart to find a short lol!

 

lol, well, if the other taillight works then you're in luck. This is because only one wire comes from the brake pedal to the brake lights in back. This wire breaks into two back by the tails somewhere. You just have to find it. OR, it could even be a bad ground on that side. Check all the wires on the "bad light side." If you have a voltage tester (multimeter) it would help the check if you are getting power there.

 

ya, was my next plan (multimetre) ... i can tell this car was bagged and neglected prior .. jus wanna get this little anoyances out of the way then focus on flushin out everything, bringin her back to life and such. So the split is located near the bulbs?

 

Using a meter will the easiest way to find an "open circuit". Just have a friend press the brake pedal and usethe meter's black lead togroundand use the red lead to the back of the socket. You should get 12 volts for each wire per filament. More than likey you will have an open circuit than a short because a "short" will blow fuses.

As for finding where the splice, you need to follow the wire harnesses for both lightassemblies to see where they start branching off.Since you have a broken circuit, you should find the wire because potentiallyit can cause headaches down the road.