New Electrical Problem

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Jul 7, 2009 | 05:45 PM

MTVette

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From: Marlboro country MA

New Electrical Problem

My 92 A4 was stored outside last night and early this morning there was a severe thunderstorm. Some water worked its way around the hood and the ECM got splashed on. When I tried to start it up, the battery was dead - about 10.8 volts, and all the dash lights go out when I try to crank it. I attached a batterey charger for several hours, and even though it was drawing a steady 5 amps, the voltage barely got above 12V. Then I tried to jump start it from a pickup truck, without success, despite the fact that the indicated voltage with the jumper cables attached was about 13.2. It made loud clicks when it tried to start. Is this the sign of a dead battery? What else might be causing this problem?

Jul 7, 2009 | 09:05 PM

gbrtng

Burning Brakes

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From: turn 12 at Road America or TX

Pull the battery and get it load tested - Advance Auto has a pretty sophisticated tester.
Other parts stores can do the job too.
Else you left something on over night - interior lights, hung fuel pump relay ...

Jul 7, 2009 | 09:17 PM

scorp508

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Joined: Mar 2000

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From: Boston, MA

Hi Mike! Does the pickup have the same terminal screws? Maybe you could just attach that battery to the car to see if it starts. I'd bring it to Advanced or Autozone and get a free test done.

p.s.

I was at the shop when Paul had your rear end out. I can't believe what happend to the half-shafts!

Jul 7, 2009 | 11:24 PM

MTVette

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From: Marlboro country MA

Sounds like a good idea. I'll pull the battery tomorrow and run it over to an Autozone for testing. It was only 2 years old, but I hope that fixes the problem.

Jul 7, 2009 | 11:26 PM

scorp508

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From: Boston, MA

I had a red top Optima die on my within a year once and got it swapped under warranty.

Jul 8, 2009 | 02:00 AM

jfb

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From: Cincinnati, Oh USA

How old is the battery? They don't last forever. Charging a dead battery for a couple hours and then jumping usually allows for a start. I suspect that your battery is toast, sounds like one bad cell and charging won't bring that cell up and jumping won't provide the current that a starter motor requires. Charge the battery overnight and see if it will crank the next morning. Measure the battery terminal voltage while someone cranks. Good batteries should not fall below 9.0 volts during cranking or they are discharged, battery terminals need cleaning, or the battery is at the end of its life. You can tell the battery state of charge by measuring the battery terminal voltage, 12.0 volts and below, discharged, 12.9 volts and above, fully charged and linear in between. You have to wait a few hours after charging to determine the state of charge by measuring the battery voltage.
My money is on a defective battery.

Jul 8, 2009 | 01:48 PM

MTVette

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From: Marlboro country MA

All fixed now. I pulled the battery and took it to the Autozone store where I bought it. They tested it and said it was OK, but the screw-in terminals looked dirty. I cleaned the terminals and lugs with bicarb, and she started right up. Thanks for the suggestions. Didn't cost me a dime!