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Battery? or Alternator? PLEASE HELP!!!

2K views 3 replies 3 participants last post by  tube 
#1 ·
So when I first got my car I noticed the headlights would flicker and the interior lights would dim when the stereo hit bass notes etc...

so I check the level of water in the battery, it's about 2" below the "UPPER LEVEL" line. So I fill it with some distilled water. I charge the battery and things seem fine.
However, after installing a larger horn, I noticed every time I beep the horn, the headlights dim, the backlighting on the stereo etc, things dim.

I go to Murray's today to borrow their battery tester. The tester tells me my battery's voltage is too high (13.2v with the engine off) and with the engine running the voltage is 14.2v. It also claims there's "Excess diode ripple voltage."

Is this just a case of a bad battery or is it my alternator? Help please.
 
#2 ·
i think you need a bass cap
 
#3 ·
Your voltages are fine. Most lead acid battery's make well over 12v.

Now being an ex-audiophile I can tell you just by the way my lights dim when I hit the power window switch, that the stock eletricla system on the subi is inadequate for a large draw condition system. To compensate you can get a CAP, but often times even with a cap your electrical system is still insufficent and you treat the symptom and not the cold.

Post stereo specs so I can further help.

FYI most stereo enthusiats dont realise that besides the added weight an aftermarket system brings to the table, overtaxing your electrical system can cause serious performance losses. Especially on FI cars where millivolts are so important.
 
#4 ·
Hahaha I have the STOCK stereo.

Well I took it to the dealership, my stock batery, rated at 490CCA tested at 207CCA. I got a brand new maintenance free battery with a 60 month warrenty that tested at 557CCA.

My lights still dim when I hit my airhorn though, I wonder if I put a capacitor in parallel with that if it will cure that problem.
 
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