2001 Audi A4 Q. Good battery, good alternator but intermittently battery found dead. No lights or radio on. When charger placed on battery fan noise is heard even before the key is turned on. The fan noise is from the passenger side of the car just behind the fog lights. It appears to be a black canister type item. Could this be the culprit. Don't, this is a care without a book and I am new at this. Thanks for any ideas
Bill
photo of what i feel is the problem


https://www.audiforums.com/forum/pic...856283&thumb=1

 

you are talking about your secondary air pump.... unless there is short or constant voltage going to it, then i doubt that is it...

alot of times what i do if i can't figure stuff out is pay someone to track down the problem, then i fix it

 

When I disconnected it, the charging of the battery went normally. Can the car be driven without this pump for any period of time or distance?

 

You will throw a code a some point (probably)
The pump is an emissions control, nice to have but not necessary for normal driving operation.

(unless I'm wrong)

 

you will throw a code, it is an emissions control device

unless you get your ecu recoded for it

 

I wish i would have known i could have done that. I put a few resistors and a couple other electrical components in there to make the ECU think that its still there.

 

yeah you'll get a check engine light but the car should be fine without it. it doesn't cost much to get a used one though. the electric pump usually goes bad but the wiring rarely does.

 

I posted a thread about this over the weekend. And I saw this thread while my car is being looked at by the Audi dealer service people. I have a 2003 A4. The fan turns off and on every 5-10 minutes and drains the battery. It sounds like disconnecting this will at least get me around till I can get the air pump replaced. How do I disconnect it, and is it easy to do?