Why have my headlight stopped working ?

[Ainsley]

First post build problem 🙂

My headlights dont work any more.  The dash lights dont work either.  But the headlight flasher and indicators work.

So I imagine its a fuse right ? Given both lights (main and dipped) stopped and the flasher, brake lights and indicators all work.  So its probably not my dodgy wiring.

But when I pulled all the fuses out, non seemed to be broken.  Do I need to look harder ? Anyone got a map of which fuse does what, so I can stick it inside the fuse box for next time.

Is it a relay ?

Am I destined to just use the car in the daylight now 🙂

 

Anyway, the sun is out so Im heading for a 1000 miles in the first week !

[OldAndrewE]

Visual inspection will not always detect a blown fuse, and apparently a continuity test is not always reliable either.  If you have got any spares you could try replacing them all.

If it is a blown fuse you have of course got the question of why has it blown

[ScottR400D]

Are the relays all seated properly? 

[Toby S]

a few points when my stop working:-

• IS it all lights (dipped, full beam and side) - - each are on different fused circuits
• If all, or just side lights working, maybe the  switch - Take out and pull apart and and keen up all contacts, could also be  a connection on the full beam/dip switch
• In cases when it was just dip or main beam not working, check behind the fuse box, as you may find on of the contacts or wires has popped out
• Also  check the earth.

I find it's usual a combination of the above

[Jonathan Kay]

Sorry, on a small screen. 

There’s a very recent thread with my suggested diagnostic pathway, which includes measuring voltage at the main light switch. Pls can someone add a link. 

Layout of fuses and relays is in the  Owner’s Handbook. But beware variations. Map your own to be certain: it will save time. 

Jonathan

[Ainsley]

Its all the headlights, which now looking at the owners handbook fuse instructions, I see is on two different circuits.

So I will have a fiddle around the back of the switch first.  I can also have a look for the annoying indicator buzzer and tape it up while Im ferreting about behind the dash.

In the meantime I need to update my insurance, there is no way Im going to do just 2000 miles a year.  I've done 200 already today and its only 3pm.  I've had the car for two weekends and put 800 miles on it 🙂

[John Vine]

3 hours ago, Jonathan Kay said:

There’s a very recent thread with my suggested diagnostic pathway, which includes measuring voltage at the main light switch. Pls can someone add a link.

This one?

JV

[Jonathan Kay]

1 hour ago, John Vine said:

This one?

JV

Thankyou, John

Jonathan

3 hours ago, Ainsley said:

 

[Ainsley]

Thanks for the link, I will go through it and hopefully it will shed some light on my problem 🙂

[BigCol]

2 hours ago, Ainsley said:

Thanks for the link, I will go through it and hopefully it will shed some light on my problem 🙂

but not initially from your headlights... 

best of luck getting a fix (given the flashers work, I’d discount fuse or relay but look at the main switch as the issue)

[Jonathan Kay]

The high beam flasher might use a different fuse from the main light switch. 

Jonathan

[Ainsley]

Yeah, I suppose as the dip, main and dash lights are all on separate fuses its probably a switch issue.

The flasher working means there is power to the lights, so its not an issue with me wiring up the lights that has failed.

I will sit in the car upside down with my head under the dash and fiddle with the switches tonight.

On a separate thought - given its not likely to be a build issue, would this not be a warranty issue and I can just get Caterham to fix it for me ?

That would save time and effort on my part.  Id rather now be thrashing the tyres off it not fiddling with it in the garage.

[John Vine]

22 minutes ago, Ainsley said:

I will sit in the car upside down with my head under the dash and fiddle with the switches tonight.

For me, that's a sure-fire recipe for a ruptured back (or something).  You might find it more comfortable just to remove the switch(es) from the dashboard.

Good luck with the detective work.

JV

[Ainsley]

Its the 620 style dash, not the push out plastic things.  They are the fancy metal toggle ones.  I think you can unscrew the ring and push them into the dash.  I will have a look later.

 

[John Vine]

Ah, posh that is.  I can see why you mentioned warranty.

JV

[Ainsley]

I've also bought some nice LED headlights, perhaps I should just throw money at the problem and get someone to fit them and fix the problem.

While its still daylight I want to spend my time driving, not fiddling 🙂

Looking at the weather forecast however, I may as well fiddle tonight and tomorrow night.

[Jonathan Kay]

2 hours ago, Ainsley said:

I will sit in the car upside down with my head under the dash and fiddle with the switches tonight.

You can sometimes get a good look with a smart ‘phone’s camera and screen. 

And I’d definitely identify and fix the problem before changing the lamp unit.

Jonathan

[Ainsley]

Right, I'm still in the dark 😞

I checked all the fuses by removing them and swopping them for spares - no effect.  Even the fuse for the flasher, which according to the other thread mentioned, was the cause of non working lights.

I checked all the wires behind the switches & fuse box.  All seem good.

Power goes to the lights as the flasher works.  But main/dipped and dash lights don't work. All the fuses are good, the car has been used for 5 days, wires are tight on the connections, its brand new.

I can only think its a dodgy switch.  They worked one day, then next morning they didn't.

I'm going to call Caterham Silverstone later and see if a warranty or money solves the problem.  

 

[Jonathan Kay]

Have you checked the voltage at the main light switch, as in the linked thread?

Jonathan

[Ainsley]

No.  I can do that tonight.  Its raining here so I may as well tinker some more.

Am I checking that voltage comes to the switch then and therefore not out of it to confirm the switch is the fault ?

 

[Jonathan Kay]

Yes, this will localise the fault: no feed to the switch, fault in the switch, fault downstream of switch (including relay)…

Jonathan

[Ainsley]

I have now tired all new fuses, unplugged and re-plugged in all the connections to the light switches, no results.  Not wanting to waste more time garaging and enjoy driving, I took it to Silverstone Caterham.  They did a quick check along the same lines as I had done and tried a new relay.  No joy, but as its nothing to do with the bits I built, its covered by the warranty.  They agreed, the fault must lie with the switch, so a new one is on order and they can fit it should I want, when it turns up.

To comply with the warranty conditions they have to do an inspection, which is fair.  In a sort of satisfying way, they came to the same conclusion as me - duff switch.

So, soon I will have working lights (probably)

[Jonathan Kay]

Solution posted in this thread:

"... a fault in the loom post switch, before headlight. "

Jonathan

[Nigel Riches]

So in amongst all this prodding and poking, was there any sign of rear lamps being energised? as when you move the switch from "Off" to "On"  there will be power to the rear lamps. Ok not the same wires as to the front lights, but a confirmation of the switch being good as far as the headlight / dip switch. 

The person you took it to for inspection was on the case, you mention the lights worked initialy and then failed, so at one time the loom was connected from battery / switch / relay / lights, so somewhere a wire is no longer attached, before the main lights "on" switch, ok the "flash" functions , different wire to a diferent switch.

Do you know where the wire jump lead is installed? Probably be able to see a different bit of wire running alongside the loom, and perhaps a new terminal somewhere, is the wire to the relay or the switch? doesn't sound like a quick fix if the loom is to be removed and replaced, probably do some in line repair.

Glad you got to the cause of this fault, so much extra tech in the later cars, none of that in the 1982 car I have from new.

[Ainsley]

The lights all worked fine for a week or two, then one day when I flicked the switch, nothing - so we had to cut the journey short as it would have been dark.

(Not sure about the rear lights, I just focused on the headlights, fuses, switches and relay)

The brake lights and indicators worked, but that's a different circuit. 

I removed and replaced all the fuses, just in case I couldn't tell a broken one from a good one.  I also checked all the connections to ensure they were good.

I changed both light switches and the dealer swopped the relay, still no lights.

The flasher switch worked, so it cant be the lights or the connection to them that I joined.

There is now a jump lead from the switch to the lights running along the loom.  All professionally done, so it will last till I find the time to get it sorted.

I suspect there is a break along the loom somewhere, but its hard to access and would take the dealer some time,

a) to fit me in to the workshop in the summer and

b) I'm off abroad soon and will certainly need the lights for that, plus its just safer to have DRL on all the time.