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Electrical Parasite

923 Views 4 Replies 4 Participants Last post by  onovakind67
I have a 2000 Camaro with an electrical parasite I found it just after I replaced my battery with a yellow top. The new battery crashed in about 3 weeks and after I replaced it I did an alternator check. It was good. Then I did a parasite check. When I disco. the neg. batt. lead and hook up the test light to neg on the battery I get a light no matter what I touch. I have pulled every fuse and relay trying to isolate it. I have heard of this happening before on an older model. So I was wandering if anybody else has encountered this and knows where it may be coming from?
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Disconnect the alternator and see if the light goes out. A leaking alternator diode can exhibit your exact issue
Doc here, :pimp:

Don't use a light..a light will light dimly under the slightest load (like computer or memory presets..)

Use a DVOM, Configured for AMPS , highest scale (usually 10 amps) , place BETWEEN the battery cable and the Battery POST..on the positive side..Take a reading, and scale it back to the lowest possible range..without pegging the readout. That is your True reading.

On a modern Vehicle with Computer, and Active memory presets, alarm, ect..It should read between 0.3 and 0.8 amps (less than an amp.) more and the system has a draw.

If that's the case, disconnect the Alternator ans recheck your readings, If it comes within spec, you have a bad Diode regulator, or Diode pack. Repair, rebuild or replace as required.

If not, Pull the fuses and Do branch circuit testing.

Not all tested will detect a reverse biased diode in an alternator, Not to mention the Kid testing it, at the zombie may know what he is doing..and pass it as good.

My Bet is on a Bad Regulator Diode..

Doc :pimp:
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Finally back....

Sorry for not getting back sooner with finals for school, work, the holidays, and the kids my schedule is pretty tight I finally got to the Camaro. I started by checking the voltage on the batt. and it was at 12.4, the disco'd. the alt., pulled the pos. lead, put the DVM on @ 20 amps with the leads completeing the circuit and it hit 1.9 off the bat then dropped to .04a and held. So I hooked the alt. back up and got no change. So I decided to go through the three fuse boxes (This is what I dislike the most about these newer cars.) and there was nothing drawing on the batt. I guess it may have just been a bad batt. from Optima... who would of thought?
Thanks for the help!
A 40 milliamp draw will take a long time to drain your battery. That's about an amp-hour a day, and the average battery is rated somewhere north of 50 amp-hours. This would require about 50 days to get the battery discharged. Hopefully you start the car more often that once every 50 days.
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