pntbllfun

hey, today i was driving around, doing a decent amount of acceleration nothing too hard tho

as i was pulling into my driveway i noticed the battery indicator came on and the voltage of my battery was at about 12 with the engine running (it is normally around 14 with engine running)

a couple minutes later i was going out to do something and car started up fine but i got a couple hundred feet from my house when i realized the battery was draining in front of my eyes. i though maybe it was the water in the battery and i needed to fill it, so i stopped on a grocery store on the way for some distilled water. i left the car on thinking that i shouldn't turn it off or it wouldn't start when i came out.

i got back in the car and the battery level was almost nothing and it wouldn't release the shift lock.

(also when the battery level was going down the ABS warning light came on, assuming it was from low voltage)

the car is currently parked in the parking lot of the grocery store. would not start (prety sure it is not the battery because after leaving it off for a couple minutes the battery charged up a little)

the question is should i get the car towed to my driveway and try to replace alternator myself (if that is infact the problem) or get it towed to a shop

old96A4

how old is the battery?? sounds like the alternator is gone if your volt gauge is correct in the car. if the battery is older than 5 years old I'd replace that too. Could be the voltage regulator buut I think that is inside the alternator. So if I put a volt ohm meter on the battery connectors and I don't get at least 13.50 volts its the charging system. most likely the alternator. Not sure how often they go in these cars. I've never replaced one. if you can find an other battery to swap and try that you can figure out if its the battery or not. Or take the battery out and charge it up and see how far it goes again back in the car and if the voltage comes back up.

rocketman4321

Well, the battery may be part of the problem or hurt by the repeated deep discharges, so I'd probably buy a new battery, put it in and get home, rather than pay for a tow. That said, I'd lean toward alternator or charging circuit, too--see recent threads on this.

Agree with the previous post. It's helpful to be methodical. Charge the battery and see if it holds charge overnight (disconnected). Or take it to Advance, AZ, Walmart or another parts store that will test it for free. (Some of them can also test alternator output.) Clean all the connections, so you're sure the alternator can put charge into the battery. Then connect the battery and see if the voltage drops overnight--check for current leaks/shorts. All these things can confuse the problem.

But if you have a known-good battery, low-resistance(clean) connections, and aren't getting ~13.5 volts, it probably is the alternator. Mine went at 60k--the worst I've seen in any car.

4Driver4

How close are you to a timing belt service? Noise must go into service position to remove the alternator; if the timing belt is due soon it might make sense to do both together.

Given how quickly the battery discharged, I'd replace both alternator and battery.

pntbllfun

the car is currently at the shop of a guy i know. i got a new alternator at autozone for him to put in.

after the battery drained i left car off for a while and came back and it was back to about 12 volts when car was on. (aka alternator not working?) so i dont think it is the battery that is the problem. hopefully the new alternator will solve the problem

4Driver4

Call him now. Return the Autozone alternator and get a good one. STFA for "Autozone"

Casavant

On previous 4000's and my current '87 4kq (230k, original alternator) the voltage regulator came out with two screws and brush kits were easy to come by and install. Not so on the A6! I figured the alternator and voltage regulator were still good as the shorter of the two brushes looked like it had been arcing. The rings the brushes run on looked to have a good bit of life left. After a few hours of playing finger contortionist under the car and some creative bench work with the throw-a-way voltage regulator (Valeo), a soldering iron, and a pair of new brushes from Faulkner Auto Electric ($4), I'm at 14 volts again.

In hindsight I wish I would have taken pictures but with the 4kq on jack stands in the middle of the garage and getting cold and dark out in the driveway I had to just get it done. Next time!

2.7Lturbo

x 0934098340834708753087


you dont buy your parts from autozone... PERIOD. especially their amazing alternator

Kristopher

bumping this old thread.

I have the exact same issue as the OP.

Bedding in my stoptech brakes with a lot of spirited driving and my battery light came on.

I've changed the alt and kept the existing battery - no charging
Bought a new battery next and tested with new alternator - no charging

I am now at this point;
1. hard driving melted my alternator wire from the alt to the starter,
2. my Bosch professional reman alternator is no good,
3. need to test my old alternator to see if it was indeed dead,

Otherwise I'm at a loss.

I thought it very interesting that the OP was driving a bit hard as well when his bit it. I initially assumed the high rpms and heavy braking put too much strain on the alternator. now I'm 2nd guessing and thinking I might have melted something?

4Driver4

There really should be a new post for this issue, not a bump.

Have you done the basic checks, like does the battery light come on when you turn the key on without starting the car? Does the car start and run with a good battery? Is the ignition switch working.

Regarding the melting, I can't determine if these are guesses or facts....is something really melted? Where?