Hi all.

Have an issue with my fiesta mk3. My headlights have stopped working. I've changed the fuses and even the relay fuse for it yet nothing. The dipped and full beam continue to work, even the flashing of the beam works on the stick.

Can anyone help or advise? Would I have to try to change both light bulbs on them?

Thank in advance

Which bulbs are not working? I thought you meant the dipped beam but you say that is working, do you mean the side lights?

Sorry. I always mix them up. The side lights are fine and working, thre di0ped do not work. Full beam and the flash both work fine.

Did they both go at the same time? If so it's unlikely that both bulbs would blow at once so it could be a problem with the electrics. But I'd change the bulbs just to see if that fixes it.

Yeah thry both did. One day they were workimg fine, the next both gone. The original relay, one of the pins were unresponsive on a voltmeter, but the new one all works and tested in a ford ka.

I'll give it a go with new bulbs. If not my MOT is due soon singer my mechanic to sort it before.

I have same problem headlights gone but side and high beam okay tried bulbs not them .ron

Check earths and multi plug has not water ingress.

did both go at same time? check fuse(s). you could also check relays. eg swap dip and high beam relays around and see what happens. Relays are behind the glovebox. I assume this is mk6 fiesta.  could be faulty stalk switch also. 

You can fix this for under $20. Disconnect battery - Remove headlamp - carefully 'split' the top of the fuse box (otherwise you have to remove the drivers wheel arch inner cover to get at the lower bolt) - cut the 5 wires (chances are they will be corroded anyway!) to the front most relay closest to the engine - splice longer wires with spade connectors and attach to new relay. Insulate as best as possible, seal the fuse box (where you split it), I used silicon in case I need to do another later! replace everything and off you go!

BTW: I'm originally from Hertfordshire but I live in the USA now, so I am somewhat assuming that the UK variant is the same as the US but not the reference to the inner arch, that will be on the passenger side there!! - Also: Hence the $20 reference = ~20 quid! given that you have VAT and we have sales tax ~6%!!

This problem needs a structured diagnosis.

1: Does the relay coil get a current through it?

 Check by listening for its operation usung somebody to help with the switching.

No noise ? Check relay voltage across coil in both on and off states.

 No change, Suspect switch. Else change relay.

2: is 12 volts getting to the relay switching contacts? 

Unplug the relay and Bridge the contact terminals with a piece of wire. If lights illuminate, the relay is at fault, if not,  check earths and wiring.

per Tomshepp, I should have mentioned that a removal of the relay should be done before my suggestions!, if there is corrosion you should see the infamous 'green/blue' dusty residue. Don't follow my suggestion unless you do!