Audi B2, (ur quatt), high beam wont stay on - Page 2

BackintheFold · 15-07-24, 09:01 AM

Usual source of problem is bad switch (the rotating one). they take so much current that the contacts burn.

>>There were several ‘high power’ wiring looms offered over the years, which used the original circuitry to simply switch an additional relay to each headlight, and provide a different route for the headlamp supply.
>>I’ve seen a few, and they were a fire hazard due to really crappy quality. But the concept is sound.

Yup-I bought Phil Payne's old ur and surprisingly it had a shitty loom with no fuse and heavy duity wires from the alternator across the engine bay to up by the radiator.
binned that!

Somewhere over the years i picked up a much better one. Fused right next to the supply from alternator.
Haven't fitted it as my lights are fine. good earths, clean switches, clean bulb contacts.

BackintheFold · 15-07-24, 09:04 AM

Quote:

Originally Posted by Adam G

I need to change the title to all headlights dim as they are staying on.

After much fiddling I found that with one bulb plugged in it is bright but each time I plug in one of the other 3 headlight bulb they all get a little dimmer, starting the car to up voltage makes no difference.

Changed the stalk switch and rebuilt the dash headlight switch, plus replaced some wiring I found with worn insulation. Still no good.

Does anyone know where the control unit is please that notifies the voice synthasizer of a headlight problem. Possibly the only thing in the circuit I haven't looked at.

Easiest thing to do is try a better earth jumpered in from the back of the headlight bulb. If that fixes it, you know you need to follow the earthing back and fix it.
If it doesn't, then its on the power side and a wiring diagram woudl REALLY help.

It only takes one rotten connection and the whole thing would be poor.

BackintheFold · 15-07-24, 09:06 AM

>>Each bulb is drawing several amps, which will also manifest as heat in other areas, like the headlight stalk, and the fuse/relay box.

Good call-For a similar issue in a house wiring, i used an IR camera to see what was producing heat, and tracked the issue that way.

Same could be done here, with JUST the headlights on use an IR camera to see what is getting hot!

15-07-24, 09:01 AM	#11
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,188	Usual source of problem is bad switch (the rotating one). they take so much current that the contacts burn. >>There were several ‘high power’ wiring looms offered over the years, which used the original circuitry to simply switch an additional relay to each headlight, and provide a different route for the headlamp supply. >>I’ve seen a few, and they were a fire hazard due to really crappy quality. But the concept is sound. Yup-I bought Phil Payne's old ur and surprisingly it had a shitty loom with no fuse and heavy duity wires from the alternator across the engine bay to up by the radiator. binned that! Somewhere over the years i picked up a much better one. Fused right next to the supply from alternator. Haven't fitted it as my lights are fine. good earths, clean switches, clean bulb contacts. __________________ 2006 A3 (daily drive) 1987 MB ur

15-07-24, 09:06 AM	#13
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,188	>>Each bulb is drawing several amps, which will also manifest as heat in other areas, like the headlight stalk, and the fuse/relay box. Good call-For a similar issue in a house wiring, i used an IR camera to see what was producing heat, and tracked the issue that way. Same could be done here, with JUST the headlights on use an IR camera to see what is getting hot! __________________ 2006 A3 (daily drive) 1987 MB ur