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Discussion Starter · #1 ·
Positive battery cables...where do they lead?

I see a red one that snakes over toward the ECU area and then disappears into the firewall...

And a black one that looks less critical (is this a ground wire?) that goes the other way around the back of the airbox then down past the turbo and disappears somewhere near the bottom of the engine...

I have what seems to be a progressive grounding issue, where I'm getting more and more symptoms of bad grounding...

First was the idle dipping and stalling with the AC on

Second was spark plug noise over the radio

Third was dim lights / no lights / failure to start even though the battery was putting out 12.54V, wiggling stuff that looked just fine seemed to bring everything back to life
 

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The red cable powers everything but the starter.

The black one goes to the starter.

How old is the battery you have? Just because it reads 12 and a half volts doesn't mean its good.

Just because you see no visible corrosion doesn't mean there is no corrosion.
 

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Discussion Starter · #3 ·
Thanks, Sharky. All good points. 58 months of use.

My first thought was the battery...but while being jumped the dash lights were dim then utterly dead, and then after unhooking the other car I immediately put the multimeter on it and the it said 12.54V.

Another thing that makes me suspicious of a grounding issue was the 100% humidity and recent rain shower; however, after blasting the engine bay with a garden hose yesterday to try to reproduce the problem there was no issue....
 

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RechtsFahren said:
Positive battery cables...where do they lead?

I see a red one that snakes over toward the ECU area and then disappears into the firewall...
that one, I dunno I haven't looked at it enough to worry yet.
And a black one that looks less critical (is this a ground wire?) that goes the other way around the back of the airbox then down past the turbo and disappears somewhere near the bottom of the engine...
Ground wire would be on the NEG terminal, so no its not. And I believe the one you are talking about is the wire comming directly from the alt, granted they take a round-a-bout way of getting there
I have what seems to be a progressive grounding issue, where I'm getting more and more symptoms of bad grounding...
Your car has two main grounds, one being at the battery. Upgrade that, looks like its 4-6awg go with 1/0 or lager if you can. The second one, which I havent found yet, is the motor to chasis ground, if you can find that one upgrade it to 1/0 or larger as well.
First was the idle dipping and stalling with the AC on

Second was spark plug noise over the radio

Third was dim lights / no lights / failure to start even though the battery was putting out 12.54V, wiggling stuff that looked just fine seemed to bring everything back to life
Also just because the battery read 12 volts doesnt mean its not going bad or already crapping out on ya. Replacing the stock battery should only cost you about 70 bucks. And it takes you longer to drive to get your old one tested, buy a new one than it does actually replacing the battery.
 

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Sharky said:
quality_sound said:
Sounds like a bad battery to me, not a grounding issue. The battery acts as a noise filter and when it goes bad it's not uncommon for spark plug noise to appear on the radio.


Paul :thumbup:
(!)

Learn something new every day! :)

HOLY SH!!!!!TTTTT!!!!!! I taught Sharky something...... :eek: I dont; know what to say..... :oops:


Paul :thumbup:
 
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