'96 Rodeo brake and ABS lights constant

1996 Rodeo
3.2 auto
165,000k

I read the past posts on this brake and ABS light nonsense. I failed state inspection today because of this. The lights have been on since I bought the thing, and the truck was passed last year no problem with the lights on. I see that the alternator seems to be the main culprit. I have no electrical problems except for maybe the radio which fluctuates in volume alot for no reason. My dash lights are somewhat dim on one side, but don't flicker. I did replace burnt out ones with 12v rather than 4v or whatever it called for.
-Battery is 12.2v
-alternator is 14.3v at the posts
-cleaned connections
Should I go ahead and replace the alternator with an OEM or high-quality one, look at contacts and connections more closely, or maybe direct my attention towards ABS/brakes? Thanks for any input.

When my '98 did this, it was the alternator. Started with those 2 lights being on (sometimes they would go on/off)--then started having issues with the tranny going in and out of "safe mode". New alternator cleared it up.

I read all the previous posts about the alternator. I wanted to make damn sure before I replaced since I do not have any other signs of voltage loss i.e. other accessories having problems. I'll find out today what the verdict is since I don't have time to diagnose and sent it to my mechanic. Did your tranny go into limp mode and other problems arise after the lights started going on, or did everything happen simultaneously? I have had those lights on for over a year now with no problems. I would ignore them, but the Communism of Virginia says the inspection will not pass. Funny thing is it passed last year.

Rear speed sensor was the problem. The alternator case was a valid explanation for this but...I knew from experience and putting a full load on the alternator with no erratic voltage readings that it wasn't the problem.

Thanks for finishing the thread and helping us learn something from your experience.

Definitely, this is best forum out there and I give a lot thanks to everyone who responds and takes the time to leave feedback. I have never owned an Isuzu and am stilling learning their little quirks.