Current dipping in car

Last week i was driving and the current in the car dipped. I thought it was because of some 8ohm speakers i put in causing the amp to trip, so i put in a pair of tweeters to change the ohmage... so i know it isnt the music causing it. So from since then anytime i drive, the current keeps dipping (the deck cuts off and comes back on, the gauges go down and come back up for like a split second, rpm drops greatly and goes back to normal). The dipping is triggered also when i flick the highbeam on and when i turn the a/c on.

things i tried:
Changing back the original headlights. (i changed to projector headlights)
Taking the fuse for the lights out and driving with it like that.
Tested the alternator and battery.
Checked the grounds.

none of these things worked... still getting the same problem. any suggestions?

Did you bring the alternator to a shop to have them check it on a machine, or did you check the voltage from the wires with it hooked up to the car? It's possible to have a bad voltage regulator, without it showing up on the machines that companies use (like Pepboys, Autozone, Advanced Auto, etc).

Have you check to see if there are any trouble codes present? It's possible to have a code present, even without the light on.

I would guess that it's either a bad voltage regulator or a bad ELD (electronic load detector).

They checked the alternator with it being attached to the car still. I also checked the codes, but my checklight was on from before the problem because of my O2 sensor. That was the only error that came up on the scan.

They checked the alternator with it being attached to the car still. I also checked the codes, but my checklight was on from before the problem because of my O2 sensor. That was the only error that came up on the scan.

That is actually pretty interesting. Unfortunately I'm out of complete ideas, but I do have a small personal experience to share, that (again unfortunately) I was never able to explain.

I actually had the same problem as you (other than my radio cutting out). The dash, dome, and headlights flashing while driving, and the rpm issue. I was able to diagnose it as a bad voltage regulator, or so I thought. The alternator was only a year old, but the troubleshooting procedure in the repair manual pointed to it. I never got around to changing it out, and then something strange occurred. My check engine light came on, and the lighting problem went away. The problem code was for my O2 sensor.

I never did any research on it or any more troubleshooting, so I'm not exactly sure how the 2 things relate to each other. Unfortunately will all the other work I need to do to get the car legal for the road again, the car's been sitting for the past year. So maybe it's something to look into, if you haven't changed it already and reset the ECU.