Electrical gremlins draining my battery
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If he had the wrong alternator as the orgional one and the parts place matched it up with the same one,,,,,,,same issue. Its a thought. My guess is the PCM isnt happy.
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From: Dyer, IN
Perhaps....I would like to see the result of a jumper wire connected to the alt connector pin D, and alt. receptacle pin D........isolating the L&F terminal feed.
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From: Melbourne FL
So far as I know the alternator I replaced was the original, as the car only had 17K miles on it when I purchased it 2 years ago. I will get the part numbers from both when I get home from work.
Instructor
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lucky likes to point out when i show my electrical ignorance. i dont fully understand how everything works.
BUT. when i am diagnosing a draw, i put my volt meter in series between the negative battery terminal and (-) battery cable, and start unplugging stuff until i find it.
good luck, hang in there.
BUT. when i am diagnosing a draw, i put my volt meter in series between the negative battery terminal and (-) battery cable, and start unplugging stuff until i find it.
good luck, hang in there.
Last edited by CoreyZ06; Oct 31, 2009 at 01:36 PM. Reason: mis-stated.
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From: Dyer, IN
Ok, to be clear. You have the main wire disconnected from the alternator, and the control circuit connector unpluged, with a jumper just between pin D of the plug and alt receptacle?
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From: Melbourne FL
Any ideas? I am down to looking at the BCM or main computer as possible problems.
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Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Yes, main power lead disconnected, still have all wires off of the B+ terminal as well, and ammeter inline on the negative terminal of the battery. Soon as I jump the D pin, it goes to 1.7 amps on the meter.
Any ideas? I am down to looking at the BCM or main computer as possible problems.
Any ideas? I am down to looking at the BCM or main computer as possible problems.
BC
Melting Slicks
Joined: Oct 2007
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From: Kinston North Carolina
The BCM will NOT be the issue! The PCM may be. I will check my car tomorrow and see what the RESISTANCE reading on pin D of the alternator wiring connector that goes to the PCM should read. I will also see if there is any voltage on that pin when the ignition is OFF.
BC
BC
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Went back and looked at my schematic and.......Pin D comes from the BATTERY and goes directly to the regulator. If your drawing current from the battery with JUST pin D connected,,,,Bud,,,your alternator is bad. Again, I will do some resistance readings tomorrow and see what pin D in the alternator reads to ground. That will be a good point to start with. Read what your Pin D in the alternator reads to ground when the alternator is completely disconnected electrically.
BC
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Just as I posted that post, I said CRAP! How the hell is the PCM getting power? Went back and looked at the schematic. 
I think we posted at the same time or close to it!
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Pin D on the ALTERNATOR reads 145.5K ohms (145,500 ohms) to engine ground.
Pin D on the harness side has battery voltage 9as indicated by the schematic.
bC
Pin D on the harness side has battery voltage 9as indicated by the schematic.
bC
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From: Melbourne FL
With everything connected except the alternator controller, I see 1.94 amps draw across the pin D connector and the alternator.
I see this on BOTH original and new alternators. No variance whatsoever on any reading I have taken so far. I cannot believe that both alternators have gone bad in the exact same manner and to the exact same degree, down to the hundredth amp.
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From: Melbourne FL
I would like to see more isolation. Remove the positive cable from the battery, connect a 18 gauge jumper from pin D of the alternator receptacle and the positive battery post.
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From: Dyer, IN
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From: Melbourne FL
Ok, I officially acknowledge that I am an electrical idiot. I need to RTFM for my test meter, and realize that I should switch the red lead to the other side port.
I am now going to rerun every test, after I finish beating my head on the desk.
I am now going to rerun every test, after I finish beating my head on the desk.
Melting Slicks
Joined: Oct 2007
Posts: 2,383
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From: Kinston North Carolina
Then get the battery load tested. When I read post #1, I thought "Bad Battery." Might not be it, Good Luck 