My main beam only works on one side. There is a few volts showing but not enough to light it. Can anyone tell me where to chase it back to? Any ideas where it splits or where I test its origin. The drivers side has 12v and is perfect but not the passengers, it only has 3v. Do both sides leave the switch or just one wire that goes somewhere before it splits further down the line. Any thoughts appreciated. 1996 300tdi 90.
Main Beam one side only
- Thread starter DougLang
- Start date
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try the wires in the inner wing, give em a wiggle, especially the black earth wires where they join into the connector block
Looking at wiring diagram, can you identify fuses 9&10? Wiring common to there then splits at fuses directly to bulbs on a blue/orange and a blue/slate. Other than that the usual suspect is any connectors en-route and of course the earth. Have you tried a known good earth to the bulb? Hope that helps...
Thanks for the replies. I ruled out earth as the other element works in the light bulb and that the voltage was showing low when I used the body as my earth on the tester. Of the two feeds to the bulb this is the low one. Could it be the switch on the column stalk? Could one work and one not from here? Do both lights go to the stalk? First post suggests not.. it suggests fault must be from fuse box to lamp... is there anything else on route?
Doug, according to wiring diag, the light switch comes before the fuses, so the if the voltage is ok up to the fuses, then it is at that point it splits to each side. Probably obvious , but have you swapped fuses or checked the voltage at the fuses? Just in case the fuse has gone high resistance or a bad joint there. Apart from that cant help with any connectors on the way. Good luck
dieselwheasel
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In the end I had to bybass the fuse box and go with a replacement single inline fuse holder as the original was not working properly. As soon as I replaced it the lights worked fine.
Ninja Haggis
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I have a similar problem tonight.
Passenger side - no issues,
driver's side - Dip only.
I thought i must have a blown bulb, so changed it .. same issue.
Electrical connector off - got 12v to the 'dip' wire between live and ground wire,
and between the dip wire and a known ground ( Chassis )
HOWEVER -- here's where it gets really weird, -
ALSO got 12v to the connector between Full Beam live, and the neutral, and also between Full beam live and chassis ...
Therefore, as I see it, - i should have main beam !
The bulb's fine, cause i swapped it to the passenger side and it works fine in there.
So - got voltage,
the earth is 'common' for both dip and full beam ... but the lord's not listening, and he's not letting there be light.
This one is a bit odd ... anyone got any ideas ?
Cheers,
Passenger side - no issues,
driver's side - Dip only.
I thought i must have a blown bulb, so changed it .. same issue.
Electrical connector off - got 12v to the 'dip' wire between live and ground wire,
and between the dip wire and a known ground ( Chassis )
HOWEVER -- here's where it gets really weird, -
ALSO got 12v to the connector between Full Beam live, and the neutral, and also between Full beam live and chassis ...
Therefore, as I see it, - i should have main beam !
The bulb's fine, cause i swapped it to the passenger side and it works fine in there.
So - got voltage,
the earth is 'common' for both dip and full beam ... but the lord's not listening, and he's not letting there be light.
This one is a bit odd ... anyone got any ideas ?
Cheers,
sounds like high resistance
Ninja Haggis
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Yes. it does.
Good thinking there Fanny .. i will go back and investigate that now.
Never happens on a nice warm summer's evening !..
Cheers bud
Good thinking there Fanny .. i will go back and investigate that now.
Never happens on a nice warm summer's evening !..
Cheers bud
Yes. it does.
Good thinking there Fanny .. i will go back and investigate that now.
Never happens on a nice warm summer's evening !..
Cheers bud
with a load on the circuit the voltage drop should appear due to high resistance.
Ninja Haggis
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Excellent. I'll go meter that out now, and see what we're getting voltage-wise.
Again, much appreciated Fanatic.
I'm fine on 240 / 415v but this auto **** confoooses the bejeesus out of me at times !
Cheers for that
Again, much appreciated Fanatic.
I'm fine on 240 / 415v but this auto **** confoooses the bejeesus out of me at times !
Cheers for that
Excellent. I'll go meter that out now, and see what we're getting voltage-wise.
Again, much appreciated Fanatic.
I'm fine on 240 / 415v but this auto **** confoooses the bejeesus out of me at times !
Cheers for that
Zs= R1+R2
or of course we could in this case look at ohms law
Ninja Haggis
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heh heh ... bloody low voltage krap ...
anyways ...
Result of metering ..
Main beam switched on, but headlight off ( i.e. just metering at connector )
- 11.98v
Connect the headlight unti back up, and meter across main beam feed and ground ...
Zero voltage .. absolutely nowt.
So i guess it cant be a short or a fuse would have gone ( can repeat the test, with headlight unti removed again, and i get my 12v back ) ... so it has to be a resistance problem , right ?
anyways ...
Result of metering ..
Main beam switched on, but headlight off ( i.e. just metering at connector )
- 11.98v
Connect the headlight unti back up, and meter across main beam feed and ground ...
Zero voltage .. absolutely nowt.
So i guess it cant be a short or a fuse would have gone ( can repeat the test, with headlight unti removed again, and i get my 12v back ) ... so it has to be a resistance problem , right ?
Ninja Haggis
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Yup ... gotcha .....
Now, the search for the offending area of the circuit begins.
As Scott of the antarctic said ... " I may be gone some time "
Cheers Fanny .. thats gave me a good start.
at least i know what i'm looking for now.
Gid lad .. Pint owed sometime
Now, the search for the offending area of the circuit begins.
As Scott of the antarctic said ... " I may be gone some time "
Cheers Fanny .. thats gave me a good start.
at least i know what i'm looking for now.
Gid lad .. Pint owed sometime
