2001 A4 2.8 Quatto

Something weird happened the other day. I was driving to the grocery store with the wife, and all of a sudden I got the dinger and EVERY light on the dash lit up, and every gauge pegged itself. I panicked, pulled over, shut the car off, restarted it and everything was perfectly normal. I thought, huh, weird, oh well, and kept on my way to the store.

On the way home (about 20 miles after the first incident), about 300 yards from my house I got the dinger again, and the battery light came on and stayed on. When I got home, I put a multimeter on the battery terminals to determine if it was the battery, or the alternator. The voltage to the battery never changed with the car off vs the car running.

Am I correct to assume that it's the alternator that took a dump since it showed no added voltage going to the battery when the car was running?

 

It is potential that it is your alternator. I had similar issues when mine went. To be more specific, it sounds like the voltage regulator in your alternator. If you can get it to a chain autoparts store, most of them can test your electrical system to determine if battery or alternator are going out. Using a multimeter on the battery can show you the voltage, but to get a true test you need a load tester. There are a couple different "shade tree" methods to do your own test but in I case like this I think you would want to know for certain.

If it is the voltage regulator starting to go out on your car, it is possible that the shop test will NOT show a problem.

If you find that it is the alternator, look into getting it rebuilt. It is much, much, much less expensive than buying a new one.

 

I've heard that Auto Parts chains in CA can no longer test charging systems on cars, as they are not licensed to do so. I don't know if that's true or not, though. Also, my closest chain autoparts store is quite a ways away. I kind of live out amongst the wineries so it's possible I could limp the car there, but getting it home wouldn't be so fun.

Also I noticed that the alternator is on the bottom of the motor. Is this another "pull the entire front end off the car" event to change the alternator? I looked for a DIY but didn't see one. I'll have to look in the Bentley, I guess.

 

not sure about the "rules" in CA for testing the system. Definitely not something you want to try and drive any significant distance to try and check out.

i did my alternator at the same time as I did the timing service so I already had the front of the car off. It is my understanding that you can get the alternator out without doing that, but IIRC you will need to get the lock carrier in service position (basically slide the raditor support forward without needing to disconnect any hoses). It's tight but there is enough room to wiggle it out.