Club 80-90 Forums

Hi. My van has just failed its MOT as the full beam indicator light isnt working.... it has worked at some point in the past but not now its seems!

I just wondered if anyone knew where I could get a replacement from, or a modern equivalent?

Also, any tips for how I approach this without breaking anything... or indeed how to check whether it is even actually the bulb that is the problem (do they fail?). The garage checked the feed to the multiplug and there is one, so the problem is within this piece somewhere. I dont have the van to check it with at this stage as its still at the MOT garage.

Pic of housing attached... the circles show broken screw holes so if anyone has a tip on how to fix them up as well that'd be handy..!

Thanks

Mine has just gone too, I will check the Haynes tonight and let you know.

Hi, I had this. I bought an LED on flying leads from Maplins in cheltenham, and soldered it onto the circuit.It was a 12v white light so I fitted a small blue rubber filter (made from my boys blue rubber head band from his swimming goggles ) into the hole where the LED pokes through been fine for about 3 years now and to the casual observer it looks the part. Mind you a repalacement bulb would have been easier but didn't think you could still get them.

ok... update... i've just put a wire across the bulb from 2xaa batteries (all i had to hand!)... i get a faint glow, so the bulb isnt knackered it seems... what should i check next - any advice?

Is there any signs of damage or broken tracks on the flexy circuit board? Also check the actual lamp holder and big multiplug socket connector for damaged/corroded pin(s)

You should in theory be able to follow the track backwards from the blue lamp It's been a while since I had my clocks out, but I think there may also be a resistor for each of the indicator lamps?

Been thinking more about this...

You said that the garage checked the feed to multiplug... do you mean a switched 12v feed when the full beam is on? If so, couldn't you run a wire from this feed, to the blue lamp, then from the other side of lamp to Earth?

If this light is the only thing not working, it seems a waste to have to buy a replacement cluster (which will cost stupid money), when it could be repaired?

nothing obvious with the tracks... i'll have a poke with a battery and a bulb. Your right - there is a resistor i think, theers a few in there, can i check these with a multimeter do you know or do they need to be wired up to a live feed for me to test?

Thats potentially a good idea about wiring up directly... so your saying solder a couple of wires direct to the led and connect these to earth and the switched supply?

I'd better also double check the garage have checked the plug feed properly as well before doing that

You could test the resistor with a meter on ohms, and check the value against a colour chart http://www.elexp.com/t_resist.htm" onclick="window.open(this.href);return false;

I doubt the resister would cause an open circuit though (stopping the lamp from working) but it is still a possibility. I'd say it's most likely an issue with the plug/socket or flexy board.

Indeed, the two pins of the LED... positive to the switched 12v (you may or may not need a resistor in-line, it depends what type of lamp/LED you decide to use), and negative to Earth (one of the pins on multiplug will be Earth)

Even if it's just a "quick fix" to get it through the MOT, then it can be repaired properly afterwards if you so wished

update pt 2.

Ok, I've managed to test a few things with a bulb connected to a couple of AA's...

i've ascertained that the led works - its dim but thats probably because i'm only using 3V (that a reasonable assumption?)
I've tested the negative track of the PCB from the LED to the bit where the multi-connector goes - its ok
I've done the same from the multi-connector to the start of the resistor - its ok
I've tried checking past the resistor but my bulb doesnt light - i'm assuming that this is because the resistor isnt letting enough power through?

So I'm starting to think theres nothing wrong (unless it is in fact the resistor) with the bulb circuit

Tell you what I'd do, given that you've got a fail and need a retest. Tap into the main beam circuit with another LED (suitable resistor for 12v) and as long as you have an indicator somewhere on your dash when you're on full beam, they'll pass it. Saves time and gives you more time to actually trace the fault. You could run it through the speaker grill if you like - long as you and they can see it, they'll give you a pass. Doesn't have to be in the same place as the original. You just have to have one.

purplecrocs wrote: I've done the same from the multi-connector to the start of the resistor - its ok
I've tried checking past the resistor but my bulb doesnt light - i'm assuming that this is because the resistor isnt letting enough power through?

You should get something after the resistor... obviously it will be a lower voltage, or higher resistance (whichever method you are using to test), but it shouldn't be nothing??

well, the method i'm using to test it is 2xaa batterys (3V) wired up to a bulb (3.5V)... so i was assuming it was stopping enough current getting through ... i've no idea how volts and resistance work though so could be very wrong!

covkid... that is indeed a plan... when you say 'suitable resistor' ... do you mean I'd need a resistor if it was for instance a 5V LED... but I wouldnt for a 12V led? or is it nothing to do with voltage and more about current.. in which case where do I start?! just tried looking on Maplin but couldnt even seem to find any 12v leds

ta

think i may have cobbled together from google my own answer to the 'what resistor' question should I have to use that method... covkid, you sound like you know what your talking about so correct me i I'm wrong...

say i got one of these:

http://www.maplin.co.uk/5mm-super-bright-leds-587264" onclick="window.open(this.href);return false;

it has a forward voltage of 3.3 at 20mA

I assume the van battery runs at about 14V

so 14-3.3 = 10.7
10.7 /0.02 = 535

i'd need a 535ohm or therabouts resistor?

Wow after reading that lot Im really hoping my bulb has gone

Mine was dim. Bought a new one from VW and hey presto it worked again