So I've given some pretty thorough use to the Search function and read up on 'Battery Light' problems, which I'm having. The battery is dying when the car is turned off, the cd player quit, tach spikes when car is running, the whole thing - and I've got a couple questions:
1. From the other threads I know I need to get the alternator tested, BUT - people have posted getting it tested while it's still ON the car and OFF the car. So my question is can I get enough info about this problem by testing it while it's still ON the car (obviously to avoid the headache, lol).
2. Grounding the battery. I've yet to find a thread that tells where the stock negative battery cable actually ends up grounding to. The stock cable was getting somewhat brittle and I thought it could be the issue so I bought a new cable and simply ground it to a screw located just above the drivers side front shock in the engine compartment. Bad idea? There didn't seem to be any change to the problem.
Also, several posters kept saying "check your grounds", as in plural. What else should I be checking?
1. Have the battery tested off the car first. If you have a charger at home and a secondary vehicle, charge it up over night and then take it to your local parts store [not your local Rip-off store in case you have that problem]. Once the battery has been given a clear bill of health, take it back home and put it back in. Afterwards, drive immediately back there and have them check the alternator while it's on the car. If it fails, take it off and have it bench tested. If it passes the bench test, it's still good [if your 2.5L has over 170k miles on it, and it has the original OEM alternator still, expect it to need replacing]. Which means, that you'll have to check BOTH battery cables and wires for corrosion and breakage.
2. That grounding spot is a good one. just make sure it's a good grounding if you know what i mean. Don't neglect the positive wire either. Check them both [with a voltmeter if you can] from the terminal to the end.
Hopefully, Bad Venge will be along sometime to shed some more light.
ACK!! Speak of the devil. he posted just before i hit 'post' lol
i would say check your belt tension but you do have grounds all over the bay look for wires screwed the the fenders and firewall take them off and clean them up they corrode and cause problems
ok well interesting update and question. after ohm and volt testing every damn fuse on the car i came across the "alternator choke" fuse. 120 AMPS !!! It was blown. The feed from the alternator arrives directly at that fuse and the power on it showed exactly what was at the back of the alternator: around 34volts. Is this correct? Does the alternator put that much out before it gets to that fuse and then after going to the computer to regulate the voltage it get split off or something?
ok well interesting update and question. after ohm and volt testing every damn fuse on the car i came across the "alternator choke" fuse. 120 AMPS !!! It was blown. The feed from the alternator arrives directly at that fuse and the power on it showed exactly what was at the back of the alternator: around 34volts. Is this correct? Does the alternator put that much out before it gets to that fuse and then after going to the computer to regulate the voltage it get split off or something?
The computer (or wherever the regulator hides out) will vary the voltage on the field coil to adjust the voltage at the output. My guess is that with that fuse gone the regulator wasn't seeing the output and couldn't control the field coil properly, which is why you got the 34 volts.
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