Background: Weak battery at start-up. It had sat on several occasions and only had about 1/3 of its cca capacity, so I got a new battery.
Next I wanted to add some more electronics gear, i.e., subs, amp, power inverter, carputer... so I got a high output alternator.
I installed both without a hitch. Upgraded the alternator to battery wire, and the ground with 2ga. wire.
All is well for about a month.
Now I go on a road trip and decide to hardwire my inverter for my laptop. I pull the positive from the post near the fusebox under the hood, and ground it on the passenger side frame rail.

Problem: After the long drive, the battery light starts coming on, but would go off once I stepped on the accelerator and increased the RPMs. Now, however, the light goes on and off under no pattern that I can see.
I removed the hardwired inverter and the light still comes on and off at random.

Question: Could what I have just descibed cause such a thing, or would it be related to some other problem?

 

anyone?

 

The alternator is probably defective.

 

Make sure the belt is tight, (not sure about a 02 but on 94's they have a auto tensioner that tends to lose tension)

If your alternator has the 2 wire square plug in make sure that is also tight. I have seen quite a few that needed the little prongs inside the clip pryed out a little to make good contact.

When the battry light is on check it with a volt meter.

If the battery light has came on at night have you noticed your lights dim at all?
Also make sure all your grounds are clean and tight.