The other thing is that my alternator was fitted with the smallest pulley that the custom builder had. He said that at idle, this alternator output would be about 70 amps.
I don't know if you can put a smaller pulley on your alternator or not.
I also added a heavier supply cable from the alternator over to the main fuse/relay box. After these changes, I don't see any voltage drop.
Hope this helps.

Wow, interesting!

I upgraded the cable that feeds the battery from the alternator, with a much beefier cable. I think the next thing to do for me would be a smaller alternator pulley. That would be great.

I think I might have found the problem with my SPAL fan controller. The way it is wired, the fan gets its power and ground from the wire harness of the fan controller. The fan controller is cabled directly to the battery - Both positive AND ground. The positive cable is fine, BUT I just noticed that the crimp connection on the controller's ground cable is kind of loose. It might have oxidized since it's a loose connection and a cheap crappy crimp connector. I'm going to check that next. Wish me luck! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Oh BTW - about the idle speed - My idle speed is not increasing. I was saying that if I manually increase the RPM a little, by just touching the gas pedal a tiny bit, that bumps up the system voltage to 14v. At 900 RPM, which is what my idle speed is, the voltage shows 12v only. The idle is steady and doesn't fluctuate on its own. This makes me think that my alternator would maintain 14v if it just could spin slightly faster (by using a smaller pulley). I will have to check and see if its pulley is removable and if I can put a smaller one on <img src="/forums/images/graemlins/kewl.gif" alt="" />

2002 Sportage 4dr 4x4 soon to undergo an Extreme Makeover!