Hi.

 

Me and my wife have a 14 plate ford focus ecoboost. 

It has developed a fault where the front left fog light is continually on, even with the ignition off.

The only way I've managed to stop it draining the battery is to remove the fuse.

When the car is on the fog light indicator is off on the dash and pressing the fog light button seems to do nothing on the switch.

 

We have booked in with ford but they say it'll be a £57 diagnostic test but I'd rather see if it can be fixed prior to it going in, even for a fraction of the price if not free!

 

Any help is appreciated!

Do both fog lights work if you switch them on normally with the fog lamp indicator too? 

7 hours ago, iantt said:

Do both fog lights work if you switch them on normally with the fog lamp indicator too? 

When turning them on it illuminates on the dash but the left one stays on and the right one doesn't come on at all.

Only way to actually turn it off right now is by taking the fuse out for the front fogs.

 

I have noticed upon putting the fuse back in that the fog that stays on flickers from time to time so makes me think there may be water getting in somewhere!

Power to both foglights is from same fuse, same relay so both should be stuck on or both not work. That doesn't make much sense. Have you checked the bulb that doesn't work? 

The earth path is via the headlights, so check the connectors at the headlights for corrosion . If you can get the fog to stay on permanently, try unplugging the same side headlight connector and see what happens

 

1 hour ago, iantt said:

Power to both foglights is from same fuse, same relay so both should be stuck on or both not work. That doesn't make much sense. Have you checked the bulb that doesn't work? 

The earth path is via the headlights, so check the connectors at the headlights for corrosion . If you can get the fog to stay on permanently, try unplugging the same side headlight connector and see what happens

 

Initially both fog lights were on but now it's just the front left that stays on, may be a coincidence that the right bulb may have gone but won't find out until tomorrow.

I'll have a look tomorrow when there's better weather to do so and see what I can find out when disconnecting headlights etc.

 

I'll update you on this tomorrow evening!

Now you've said both were staying on initially. I'm now guessing the fog lamp relay is stuck on. Sounds a bit brutal but give the bcm a bit of a thump.

7 hours ago, iantt said:

Now you've said both were staying on initially. I'm now guessing the fog lamp relay is stuck on. Sounds a bit brutal but give the bcm a bit of a thump.

When you're referring to the BCM, what is that and where can I find it?

Yeah, but I think the relay could be intergrated into the bcm . The bcm is the fusebox in the passengers footwell

2 hours ago, iantt said:

Yeah, but I think the relay could be intergrated into the bcm . The bcm is the fusebox in the passengers footwell

Okay. I'll give it a thump once I'm finished work.

Is it a common fault for the fog relay to stay on?

1 hour ago, Markph123 said:

Okay. I'll give it a thump once I'm finished work.

Is it a common fault for the fog relay to stay on?

Not that I'm aware of. 

23 hours ago, iantt said:

Not that I'm aware of. 

I've had a thump at it and it seems to not do anything.

I'm going to try disconnecting the battery tonight and leaving it off for 30 minutes to try resetting the relays.

 

Seems a shame the relay is actually integrated into the BCM.