A8L electrical problems. Help
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AudiWorld Junior Member
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A8L electrical problems. Help
I have a 2003 audi A8l. New battery, new alternator, lots of work done. Never charges at 13.5-14.5 volts. Always low at 12.2 or 12.7. Not the alternators problem, not the new battery either. Took the junction underneath passenger side wheel well apart, cleaned contacts, then put back together. Now the car doesn't start at all. Starter clicks. Battery is good at 12.5v, and even when jumped from another car, the starter clicks. The wires going from the battery to the alternator are good, checked with multimeter. When checking for parasitic draw, theres 3.2 amps. Thats not good, and I am working on finding the problem, but that wouldnt stop the car from starting.
When connecting battery terminals, they dont spark at all, like im hooking up nothing. Ive checked every fuse, in all the different areas, none are blown.
This is majorly confusing.
When connecting battery terminals, they dont spark at all, like im hooking up nothing. Ive checked every fuse, in all the different areas, none are blown.
This is majorly confusing.
AudiWorld Senior Member
Joined: Oct 2005
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Crazy parasitic draw, I would suspect the alternator diodes. I would charge the battery (disconnected) and check it, disconnect the alternator, then start the car and see what voltage it puts out when run disconnected from the car. You'll need another battery for that test but it can be a small motorcycle or old UPS battery or whatever.
Also look for AC voltage from the alternator.
I am replacing my voltage regulator in the next day or two so I will have some fresh insights on the charging system and can measure stuff while I am at it, if that helps.
I understand you do not think the alternator is bad but where is your voltage? And 3.2A is a lot of parasitic draw but there are a lot of 10A and 20A draws on the car, the alternator working properly will not mind a 3.2A draw and should still put out something like 14v
-Joel.
Also look for AC voltage from the alternator.
I am replacing my voltage regulator in the next day or two so I will have some fresh insights on the charging system and can measure stuff while I am at it, if that helps.
I understand you do not think the alternator is bad but where is your voltage? And 3.2A is a lot of parasitic draw but there are a lot of 10A and 20A draws on the car, the alternator working properly will not mind a 3.2A draw and should still put out something like 14v
-Joel.
Thread Starter
AudiWorld Junior Member
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Ive done quite a bit more testing. thank you for responding. I re checked the draw, and i forgot to trick the trunk into thinking it was closed. It doesnt have a power draw. The problem ive diagnosed now is that i get 12.5 volts from the battery, 12.5 volts at the connection in the passenger wheel-well, when i turn the key to start it, there are 0 volts going to the front wiring harness (starter and alternator). key off, 12.5 volts. key on, 0 volts.
AudiWorld Senior Member
Joined: Oct 2005
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Typically that is a bad or loose battery cable end or similar connection point. Try adding a jumper cable to ground and jumping power to the junction in the RF wheel well as a test. Avoid piggybacking these connections onto the battery cable connections.
If the connection to the battery can't get tight enough, a small piece of beer can aluminum helps out until it can be properly repaired.
If the connection to the battery can't get tight enough, a small piece of beer can aluminum helps out until it can be properly repaired.
Thread Starter
AudiWorld Junior Member
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I found the ground schematics for the car online, went through and sanded every single one down. the engine ground is the most important. I hope nobody else makes the same stupid finding.
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