2014 Ford Focus No left brake light and 3rd brake light burns dim all time
2014 Ford Focus SE / 3rd brake light went out. Bought replacement. By the time it got here and I was replacing it I noticed the Left brake light out. Replaced 3rd brake light and during the daylight it came on when brakes applied. As it got closer to dark I noticed it was burning dim all the time and no way to turn it off without unplugging. Well by this time I had already worked on the left brake light. I had proven the bulb was good by removing it and testing with my multimeter also sticking 12v to it from a battery. I then started trying to work my way backwards from the brake light. I started at right behind the socket and pierced wires with my test light to see if I had juice there while I had someone else step on the brake with the switch on. No good. Took my battery and rigs some cables and pierced the wires right behind the brake light socker and applied 12v to the wiring. No go there either. I am thinking maybe the socket is bad but then again I don't no voltage to the wire going to the socket with someone foot on brake and switch on. #rd brake light burns dim so its seems like stray voltage due to a short in the wire somwhere. I don't want to be plugging and replugging 3rd brake lights all the time
Hope the diagram helps? the stop lamps get voltage from bcm. It appears the stop lamp switch signals the bcm then the bcm sends voltage for stop lamps. I'm not saying replace bcm it needs to be diagnosed properly. Hate to see you replace something and it not fix the problem.
Thanks for this info. Is it possible for the BCM to send voltage down the right side and not down the left side? There are a couple more possible culprits I'm going to have the mechanic look at since this car was previously towed behind a motorhome and I'm not sure what non OEM wiring may still exist if any that could have gotten damaged over time underneath the car. Any way the dealer and most independent shops charge about the same hourly rate which close to $90 an hour. Can't afford them to spend to may hours chasing a problem like this that could take for ever