Mechanics

DRAIN ON BATTERY

2000 Jaguar XJ8

Engine Mechanical problem
2000 Jaguar XJ8 V8 Front Wheel Drive Automatic 66000 miles

My battery was " suddenly" dead last week when I came out from work. The car was jump-started and AAA said the battery was fine but something was putting a drain on it - most likely an electrical short. I have had 2 places do a battery load test just to be sure it is definitely not the battery. One said replace the battery but it could also be the alternator going bad or a short or both. The other (chain that specializes in batteries) said it was not the battery but the alternator only had output of 13 amps and probably needed replacing. He also " tested" the battery for a short in some other area by removing the negative cable and touching a wrench to the battery post to see if it would spark which it did. So he said I could have two things going on. Do you agree with these dx? What should I do at this point? I do not want to get stranded but I also do not want to get ripped off by my mechanic or a dealership. When I called my mechanic about this to begin with he immediately said replace the battery.
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Sam2559
September 29, 2008.



If the load tests done on the battery and alternator satisfys you-get the electrical system check for a short circuit


http://www.2carpros.com/forum/automotive_pictures/12900_parastic_draw_1_33.jpg


Rasmataz
Sep 29, 2008.
I do not feel like you answered my question. You did not address the amp read-out nor did you tell me if you agreed or disagreed with the previous suggestions. As I am not a mechanic and the reason I came to you with the question, telling me if I am satisfied with the battery and alternator tests does nothing for me. How am I supposed to know if those should satisfy me or not.

Tiny
Sam2559
Sep 29, 2008.
You've been bringing it in to the people that specializes in battery and alternator. If this items are being load tested it will finger it at no time between the two.

Okay-get the battery load tested for 10secs if it doesn't hold 9.6 volts on that time frame-its defective.

Same as the alternator if it doesn't come up 10% within the alternators's output its defective

NOTE: but the alternator only had output of 13 amps and probably needed replacing. Is this readings being taking under a heavy load?

Last
My battery was " suddenly" dead last week when I came out from work

I gave you how to check a battery drain-I'm suspecting a short circuit in the electrical system that will cause that failure last week.

Rasmataz
Sep 29, 2008.