davesb5s4

2000 b5 s4
I believe I have a bad alternator cause using headlights, a/c etc drains my battery. Money is too tight right now for the repair and I work from home and don't do much driving so I put my battery on a charger after driving. Sometimes I do a short trip at night using the headlights which drains my voltage. I was on my way back from a longer trip and the voltage dropped to around 8 volts and the xenons start to flicker/strobe. This happened before and its not a problem after a nights charge.
This time after a charge I was going to go to the store but could not get the xenons to work. battery is fully charged and showing good voltage and I can get the high beams to work, but not the xenons.
Any ideas on the issue? Did I damage them?

EuroXS4

Voltage could be good but the amperage might not be there.xenon draw alot of amperage on inital start up.So you just might not have sufficient amperage for the ballast to kick on.I dont think there damaged to be honest.But you never know.Mostly its just the battery not having eoug amperage to fire the ballasts.

Chris's S4

Did you get the car started before striking the Xenons? If ya did, then there's more than enough amperage. But... after a start up with no running alternator, it could drain the battery to the point where they won't strike. So... best thing to do.. Hot wire only one, directly to the battery and test them each independently. That way you can identify the problem. If your still having an issue, then chances are it's the xenons. Make sure give the battery and good solid charge. Then try the light. Forget about starting the car at this point.

Another thing.. if that battery is good, it should have NO problems striking the xenons on without the engine running. I do it all the time, but then again I have a good battery. So you can try that or the other way I mentioned by hot wiring them. If you hot wire them, then you bypass any wiring harness which may have a fault for whatever reason now. Not saying your wiring is broken.. don't jump to conclusions... Just keeping the idea as a possibility.

Anyways, run the test and go from there, then report back. Have you checked the idiot switch yet? AKA the Fuse? just putting it out there cuz most of us usually check it out after throwing money at the car. LOL... Take a look. Good luck

Chris