Audi 80 b4 headlight question

sjp001 · 04-08-18, 11:23 PM

Hi all,

I'm afraid I know very little about electronics, but any help would be appreciated...

Basically one night both headlights on my b4 audi 80 tdi went out on dipped beam, but the side lights and full beam were fine. Fuses were fine. So I bought a second hand switch (steering column one with the stalks for indicators and lights) and the lights were fully functioning again. Less than a week later and I've lost dipped beam again. Any thoughts? Is there a relay for the lights somewhere, as I can't find any info about where it is but presume there must be one somewhere. I assume there will be one in the area behind the drivers side parcel shelf thing. Also I suppose it could be possible that the switch has failed as it was second hand?

Thank you very much in advance for any help!

theschmallfella · 05-08-18, 12:40 AM

I had this issue some years back with my 200, apparently it's a common fault with the C3 100/200 that there's too much voltage going to the headlight switch causing it to burn out the connector block (as was the case with mine) or the switch itself would fail. I purchased a kit online which had two relays and wiring which when installed took the load from the 12v going to the headlight switch. Now, this is a few years ago, possibly 7 years. if you have a look here: http://audi100.net/Shop/shop.html and scroll to near the bottom of the page you'll see exactly the kit I'm talking about under 'Audi Lichtupdates'. I didn't buy from this site, I'm sure it was from ebay but you get an idea about what I'm on about. Unless any of our learned people here can say otherwise I think this is the solution to your problem, and I can safely say that I've never had a problem with the headlight switch since.

sjp001 · 05-08-18, 03:47 PM

Thank you so much for taking the time to help me theschmallfella, it is really appreciated! I think you have hit the nail on the head, as that would explain why I can't find a headlight relay and the switch failing. Also many thanks for linking me to the site, as it looks like I can get everything I will need there.

If anyone knows of a relay kit available swiftly from the uk then let me know, otherwise I will order from the site you linked to later on tonight.

Many many thanks for the help as it was baffling me!

John. · 05-08-18, 04:02 PM

Quote:

Originally Posted by sjp001

If anyone knows of a relay kit available swiftly from the uk then let me know....

It's the same as if you were wiring up spot/fog lights, so you could just buy a couple of (preferably fused) relays, wire and connectors. Would save you a bit of money?

sjp001 · 05-08-18, 09:52 PM

Thank you John that's a great idea, would that be a 12v 10amp relay?

John. · 06-08-18, 04:21 AM

Quote:

Originally Posted by sjp001

Thank you John that's a great idea, would that be a 12v 10amp relay?

10 amp would be fine.

sjp001 · 06-08-18, 09:06 PM

Perfect, thank you for the help! Hopefully I'll get them working again reasonably swiftly.

sjp001 · 14-08-18, 08:42 PM

Just an update to let anyone in future know that I fitted relays to the dipped and main beam and all seems to be well again.

Thanks for all the help everyone!!

05-08-18, 12:40 AM	#2
theschmallfella Grown up member Classic Audi Club Member Join Date: Sep 2011 Location: Back in the Emerald Isle Posts: 772	I had this issue some years back with my 200, apparently it's a common fault with the C3 100/200 that there's too much voltage going to the headlight switch causing it to burn out the connector block (as was the case with mine) or the switch itself would fail. I purchased a kit online which had two relays and wiring which when installed took the load from the 12v going to the headlight switch. Now, this is a few years ago, possibly 7 years. if you have a look here: http://audi100.net/Shop/shop.html and scroll to near the bottom of the page you'll see exactly the kit I'm talking about under 'Audi Lichtupdates'. I didn't buy from this site, I'm sure it was from ebay but you get an idea about what I'm on about. Unless any of our learned people here can say otherwise I think this is the solution to your problem, and I can safely say that I've never had a problem with the headlight switch since.

05-08-18, 03:47 PM	#3
sjp001 Grown up member Join Date: Jan 2014 Posts: 62	Thank you so much for taking the time to help me theschmallfella, it is really appreciated! I think you have hit the nail on the head, as that would explain why I can't find a headlight relay and the switch failing. Also many thanks for linking me to the site, as it looks like I can get everything I will need there. If anyone knows of a relay kit available swiftly from the uk then let me know, otherwise I will order from the site you linked to later on tonight. Many many thanks for the help as it was baffling me!

05-08-18, 09:52 PM	#5
sjp001 Grown up member Join Date: Jan 2014 Posts: 62	Thank you John that's a great idea, would that be a 12v 10amp relay?

06-08-18, 09:06 PM	#7
sjp001 Grown up member Join Date: Jan 2014 Posts: 62	Perfect, thank you for the help! Hopefully I'll get them working again reasonably swiftly.

14-08-18, 08:42 PM	#8
sjp001 Grown up member Join Date: Jan 2014 Posts: 62	Just an update to let anyone in future know that I fitted relays to the dipped and main beam and all seems to be well again. Thanks for all the help everyone!!