Chrysler Repair: Battery Light on/alternator passes test, chrysler cirrus lxi, 1996 chrysler cirrus

Question
QUESTION: Hi,
I have a problem where the battery light came on and stayed on, usually after 5-10 min of driving; I had both the battery and alternator tested, and both were read to be fine.

Recently I noticed that my dashboard lights were weak, and when I stopped the car, it would not start. I waited about 5 min, and it started, albeit struggled to do so.

I did the key code, and it said code 12 and code 55.

Where should I start with this?
The car is a 1996 Chrysler Cirrus LXi

Mahalo

ANSWER: Hi Mike,
The observation "after 5-10 minutes of driving" may be the relevant item. Was the battery light 'on' when the alternator was being tested?
If not, then I would have it tested under those conditions. It may be that it is failing but only after running for 5-10 minutes does it manifest that behavior.
If it passes that test the the alternative is to look for another component in the electrical system that is drawing excessive current after 5-10 minutes, but that would almost certainly blow a fuse if it was so bad as to turn on the battery light.
I suspect the alternator.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi Roland,
Thanks for the quick reply; the battery and alternator were tested once when the light was on and then once when off, and both times they read good, so I'm at a loss from there.

Assuming it is the alternator, I have 2 questions -
1-How do I check? Since I already have had the alternator and battery tested, how could I isolate the alternator to test?
2-How hard is this to replace? I would be leaning to picking up one from ACDelco and installing it myself if it isn't too difficult.

Just as a curiosity, what electrical components could cause the excessive drain, and how could I check?

Thanks

Answer
It could be almost anything that would pull down the voltage while you are engine is running (it doesn't sound like a problem that drains the battery when the ignition is off). You might have to check to see if any of the circuits is drawing high but without blowing a fuse using an amp meter in series with each fuse. What is the voltage showing on the battery when the light is 'on'.
I would suggest first that you check the fat red wire at the alternator and follow it along its route back to the battery. You will find a fusible link, and that device may be 'opening' when is use, so check to see if it shows continuity once the warning light is 'on'. It might be getting ready to 'open' all the time. It is a wire that acts like a fuse so that could explain your problem.
The alternator removal is a 10-step process. I can xerox a page or two and mail them to you which show how to do this. Let me know a postal mailing address.
Roland