Hi everyone,

I recently noticed my read passenger brake light was out and have now replaced the bulb on my 2009 fiesta.

Since doing this, I've noticed the passenger sidelight and rear passenger sidelight don't work either. I don't think this problem was there before but I could be wrong.

I've checked the fuses but these look good (22, 14, 15).

Does anyone know what might be causing this?

thanks in advance

Jim

 

Hi Jim. I had a similar problem on my focus, whereas one side wouldn't work. The thing that threw me was it came on briefly when I unlocked the car. I ended up ripping my seats out as I was convinced it was a wiring issue so I was following the wires back to the BCM. In the end, I discovered it was a dodgy bulb in the rear fitting. The BCM was sensing the fault and shutting off that circuit to protect it. I dont know if the brake light bulb is a double filament, but its possible that you've mistakenly put it in the wrong way around. Either way, I would check the bulbs as that's the easiest option. 

4 hours ago, Nathan Buffery said:

Hi Jim. I had a similar problem on my focus, whereas one side wouldn't work. The thing that threw me was it came on briefly when I unlocked the car. I ended up ripping my seats out as I was convinced it was a wiring issue so I was following the wires back to the BCM. In the end, I discovered it was a dodgy bulb in the rear fitting. The BCM was sensing the fault and shutting off that circuit to protect it. I dont know if the brake light bulb is a double filament, but its possible that you've mistakenly put it in the wrong way around. Either way, I would check the bulbs as that's the easiest option. 

Hi Nathan, thanks for the advice. I'm pretty sure it the rear bulb I replaced was a double filament. When you say I might have put the bulb in the wrong way around, I didn't know there was a right/ wrong way of doing this. Will refit it and see if that solves the issue.

Hi Jim. The lugs on the side of the bulb are at different heights. 

And this needs to match up with the holder. If it's in the wrong way, then your brake lights will be at different brightness as the side lights are a less wattage. 

It's also possible that you haven't put it in the wrong way, but in taking the light fitting out, you've disturbed the connection on the side light. The bulbs usually earth on the outside of the bulb and I have found that they do corrode sometimes. A good clean up with sand paper and a spray with wd40 will sort this out. One thing to note is the side lights are referred to as Position Lights when looking in your manual or checking fuses. To me, position lights sounds like the indicators, but there you go!!!

@Nathan Buffery I had indeed managed to put the bulb in the incorrect way. Thanks for saving me many hours of frustration!