I have a brand new alternator and battery, I haven't had any issues with them for a while. There was some initial problems due to me not tightening the ground on the alt, but that was sorted out a while ago.

I noticed my battery light on very dim the past couple weeks, as well as my head unit acting up. Every other time this has happened I ran in to issues a few weeks later. Like when my alt went on me the first time.

Well I hooked up my fogs, not running anything crazy, just H3's. I had my car warming up outside of work with everything going... radio, lights, fogs, heater, rear window defrost, wipers.. and when I went to leave my battery light came on. Not at full capacity, but brighter than it usually is. Still fairly dim.

I shut off everything but the essentials, (head lights, wipers) The battery light turned off, and everything was fine.

I checked all my connections. Leads to my battery are tight, alt is good, etc. However, if I turn on anything with a drain such as the heater blower, the light will come on very faintly.

Should I be worried, or is this just because I am running so much crap, that the car can't side and idle with this junk going? I've had the new battery/alt for a few months now and had no issues after the initial loose wire.

The fogs might contribute, but I ran them in my '78 and didn;t have this problem.

Oh, I should mention I also recently had to tighten my belt because it was a bit loose and squealing in the cold.

make sure ALL your grounds are tight under the hood

E21's can be known to have faulty tensioner brackets that slip.

Try a belt one size up/down and see if tightening the belt in a different position will make a difference.

As a last resort replace the bracket & hardware. Also our alternators are (iirc) 65amp... ever think about getting your old one rewound up to 100amps or running an e30 alt (fittment issues with fuel dist)?

Did you clean that connection that bolts to the positive battery terminal? Take it all apart and clean it good.