B7 headlight issues

[blergen]

Hi all, hoping for a bit of guidance.

Message popped up on the dash to check right low-beam headlight. Replaced bulb, still no good. Swapped bulbs from left to right. Both bulbs are good.

So, figured it might be the ballast. Dropped the front bumper, took both headlight assemblies out. Thought the easiest way to test the ballast is to swap left and right and see what happens. Swapped ballasts, plugged headlights back in and now they both don't work. LED running lights still work on both sides but no low or high beam.

So I removed the assemblies again swapped the ballast back and now we're back to the left low beam working but no right.

Didn't make sense to me, thought I must have missed a connection or something so I did it all again with the same result.

Any ideas what's going on? I don't understand why the good ballast in the left wouldn't work when swapped to the right.

[sn809]

Hi all, hoping for a bit of guidance.



Any ideas what's going on? I don't understand why the good ballast in the left wouldn't work when swapped to the right.

I think that is your answer. There is probably an issue with Ballast as well as fuse/wiring on the right side. Have you used an amp meter and checked the current

[blergen]

I'm resurrecting this thread, as I still haven't fixed this!

Left side low beam works, right side doesn't. I bought a new ballast and installed on the left. Doesn't work. Swapped left and right ballast. Left still works but right does not. Swapped left and right bulbs. Left still works but right does not.

So I know the ballast and bulbs are all good, as any combination of them works on the left side

The high beam and led running lights on the right still work, so the assembly is getting power.

It's doing my head in - any ideas?

[sn809]

You should change the fuse and definitely get some one to check output via voltmeter.
It could be a bit of wiring is frayed (-worse case scenario) due to which supply is decreased.

[blergen]

Thanks mate. I tested the fuse with a multimeter and it's fine. Taking it to an auto electrician to check as it's now beyond my capabilities to resolve I think.

[sn809]

What was the outcome>>

[blergen]

Auto electrician is stumped, it's with a vw/Audi specialist today. I'll let you know what they come up with.

[blergen]

It was the power module in the steering column

[blergen]

Which is a $1300 part

[VW Convert]

Which is a $1300 part

Ouch! Add your auto elec's time and the VW specialist's time that's an expensive headlight fix.