Hi, I have a 2012 Focus 1.6 Titanium. Since bought 2nd hand 3 weeks ago I’ve had an intermittent fault - when the car ignition is on or the engine running, the side lights come on and stay on whatever the lights selected on the knob. Even when on auto or off, and you can’t flash the beam either. The lights also show on the dash diagram. The lights do switch off when the car is off and locked.

the switch has been changed so it’s not that. The fault is consistent for 2 or three drives and the it’ll work fine for a similar period. It’s only changed once that I’ve noticed whilst driving (with the lights going from normal to sidelights constantly on). Turning the ignition or switching the car off and on doesn’t seem to reset it.

 

it’s doing my head in! Hate electrical problems! Any ideas?

The first thing that comes to mind is something that's been widely discussed on here. Due to a problem with the screenwash pump seal water can find it's way by capillary action back through the loom to the Body Control Module (BCM) which is the fusebox in the passenger footwell under the glovebox. This causes corrosion of the connector contacts and can throw up all kinds of weird faults.

Are you perhaps confusing 'Side Lights' (now referred to as Parking Lights) with Day Running Lights (DRL), which have been a legal requirement in the UK since 2011 ?

DRL will always come on with the ignition and stay on they are not controlled by the light switch. You can check to see if the lights that are on are parking lights or DRL's by looking at the rear lights. If the front lights are on and the rear lights are off then they are DRL's.

4 hours ago, unofix said:

Are you perhaps confusing 'Side Lights' (now referred to as Parking Lights) with Day Running Lights (DRL), which have been a legal requirement in the UK since 2011 ?

I’ll check, but pretty sure the rear light are at least partially on too. Plus I don’t think DRLs would show as me having the lights on via the dashboard ‘car’ diagram?

plus when this happens I can’t select anything else via the light selector - they’re on the same whatever I select. So I can’t currently drive it at night

but I’ll check to make certain. appreciate the response

5 hours ago, mjt said:

The first thing that comes to mind is a something that's been widely discussed on here. Due to a problem with the screenwash pump seal water can find it's way by capillary action back through the loom to the Body Control Module (BCM) which is the fusebox in the passenger footwell under the glovebox. 

Thanks and I’ll definitely check and let you know! I presume it can only be a few things - the dash switch (which has been changed, so shouldn’t be), the wiring/loom, fuses, or whatever gubbins provides the ‘brains’. Thanks for the heads up and I’ll take a gander

I think it's advisable to disconnect the battery before detaching any connectors.

It's also possible for water to find it's way into the unit from above if there's a leak from the windscreen or ventilation system. The BCM is not just a fusebox but, as it's name implies, is a computer that controls most of the body functions like lights, wipers, windows etc.