Xenon Headlights (2011 Mk4 Mondeo) - both failed at once?
Discussion
Driving late last night, I put the full beams on for the first time in a while. As I was driving both full beams failed and went back to dipped beam.
I checked the fuse and all OK.Surely both bulbs can't fail simultaneously?
Ordinarily I would just bung in some replacement bulbs and see or check with a multi-meter etc. However with Xenons I am looking at £100 a pair or some such craziness. I do fancy getting something a bit brighter as I will likely be doing a lot of night driving soon but i don't want to spend the cash if there is some other fault.
Is there any way I can test a xenon bulb? Any common faults with these? Is it likely that both failed at once?
Thanks in advance.
I checked the fuse and all OK.Surely both bulbs can't fail simultaneously?
Ordinarily I would just bung in some replacement bulbs and see or check with a multi-meter etc. However with Xenons I am looking at £100 a pair or some such craziness. I do fancy getting something a bit brighter as I will likely be doing a lot of night driving soon but i don't want to spend the cash if there is some other fault.
Is there any way I can test a xenon bulb? Any common faults with these? Is it likely that both failed at once?
Thanks in advance.
Does the low beam stay on with the high beam on that car? On my Mondeo it's one or the other.
If the low beams switched back on when the high beams went off that would make me suspect a switch/wiring type of problem. If the low beam stayed on the whole time that's consistent with a bulb or fuse failure. I guess it's possible that one bulb blew and caused a surge that took out the other one - I haven't seen that on a car, but I've seen it with mains voltage bulbs which I guess are broadly similar.
If the low beams switched back on when the high beams went off that would make me suspect a switch/wiring type of problem. If the low beam stayed on the whole time that's consistent with a bulb or fuse failure. I guess it's possible that one bulb blew and caused a surge that took out the other one - I haven't seen that on a car, but I've seen it with mains voltage bulbs which I guess are broadly similar.
The dipped beam did stay on when the full beams failed. Difficult to know without taking the headlamp assembly apart. The main bulb is concealed behind a very domed lens.
I do have the blue light on the dash light up so was hoping that the switch is ok. Perhaps I have a duff relay after all?
For a laugh I called the local ford dealer for a price on replacement bulbs. £162 each!! Yikes.
I do have the blue light on the dash light up so was hoping that the switch is ok. Perhaps I have a duff relay after all?
For a laugh I called the local ford dealer for a price on replacement bulbs. £162 each!! Yikes.
GreenV8S said:
Does the low beam stay on with the high beam on that car? On my Mondeo it's one or the other.
If the low beams switched back on when the high beams went off that would make me suspect a switch/wiring type of problem. If the low beam stayed on the whole time that's consistent with a bulb or fuse failure. I guess it's possible that one bulb blew and caused a surge that took out the other one - I haven't seen that on a car, but I've seen it with mains voltage bulbs which I guess are broadly similar.
If the low beams switched back on when the high beams went off that would make me suspect a switch/wiring type of problem. If the low beam stayed on the whole time that's consistent with a bulb or fuse failure. I guess it's possible that one bulb blew and caused a surge that took out the other one - I haven't seen that on a car, but I've seen it with mains voltage bulbs which I guess are broadly similar.
breamster said:
GreenV8S said:
Cool - good to have a resolution.
Bum. Spoke to soon. Fuse has blown again. Does anyone have any ideas? I'm not actually sure now if I have halogen or xenon? How can I tell?Thanks.
If the fuse keeps blowing check the contacts in the fuse holder - poor contacts will lead to heating which will cause the fuse to break down, and also accelerate corrosion which makes the problem even worse. The heat can also cause the contacts to relax so they don't clamp onto the fuse properly.
GreenV8S said:
If the fuse keeps blowing check the contacts in the fuse holder - poor contacts will lead to heating which will cause the fuse to break down, and also accelerate corrosion which makes the problem even worse. The heat can also cause the contacts to relax so they don't clamp onto the fuse properly.
A bad contact at a fuse will burn it and never blow itbreamster said:
Bum. Spoke to soon. Fuse has blown again. Does anyone have any ideas? I'm not actually sure now if I have halogen or xenon? How can I tell?
Thanks.
https://www.youtube.com/watch?v=XNrIW9SKlasThanks.
Take a look at the video, you will be able to see the gear fitted for Xenon's
Post back when you know what you have fitted, no point in guessing is there
Righty ho.
I've had a look and I'm pretty sure they are Xenon. They have what look like ballasts in the back of the headlight unit.
Difficult to have a proper look - the joys of leaving for work in the dark and getting home in the dark and no cosy lit garage to work in.
I've changed the fuse again albeit with a different brand of fuse just in case.
The fusebox look spotless as it is under the glove box inside the car. Both headlamps are dry and there is no condensation in either of them.
Lets see if I blow them again over the next few drives.
I've had a look and I'm pretty sure they are Xenon. They have what look like ballasts in the back of the headlight unit.
Difficult to have a proper look - the joys of leaving for work in the dark and getting home in the dark and no cosy lit garage to work in.
I've changed the fuse again albeit with a different brand of fuse just in case.
The fusebox look spotless as it is under the glove box inside the car. Both headlamps are dry and there is no condensation in either of them.
Lets see if I blow them again over the next few drives.
repeatedly failed fuse = too much current for the circuit, and the fuse.
Something is drawing too much current.
I don't know enough about the electronics of Xenon bulbs to say about that, but a worn bit of loom and a short to earth is the other explanation.
Try a multimeter across the wires between lamps and fuse, ignition off, jiggling the circuit. Does an earth suddenly appear?
John
Something is drawing too much current.
I don't know enough about the electronics of Xenon bulbs to say about that, but a worn bit of loom and a short to earth is the other explanation.
Try a multimeter across the wires between lamps and fuse, ignition off, jiggling the circuit. Does an earth suddenly appear?
John
Penelope Stopit said:
What is the number of the fuse that keeps blowing?
Have you located a wiring diagram and if so can you share it so that I can take a look?
Thanks Fuse is F9 under the glovebox - will do some googling to try and find a circuit diagram - very logical I should have thought of it!Have you located a wiring diagram and if so can you share it so that I can take a look?
tapkaJohnD said:
repeatedly failed fuse = too much current for the circuit, and the fuse.
Something is drawing too much current.
I don't know enough about the electronics of Xenon bulbs to say about that, but a worn bit of loom and a short to earth is the other explanation.
Try a multimeter across the wires between lamps and fuse, ignition off, jiggling the circuit. Does an earth suddenly appear?
John
I'm not particularly skilled with a multi-meter but I've jiggled as much as I can with no sign of an intermittent earth.Something is drawing too much current.
I don't know enough about the electronics of Xenon bulbs to say about that, but a worn bit of loom and a short to earth is the other explanation.
Try a multimeter across the wires between lamps and fuse, ignition off, jiggling the circuit. Does an earth suddenly appear?
John
On the occasions I have blown the fuse it is when I've had them on for 20+seconds driving at night. They have not blown when I have used them flash people out of junctions etc. Not sure if that makes any difference.
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