Toyota Repair: 2001 Toyota Sienna - Battery warning Light not turning off, daytime running lights, resistance measurements

Question
recently the 2001 Toyota Sienna failed to start. The voltage of the battery was 10volts while car was off, and dropped to 6 volts after I jumped the car.

This led me to believe that a faulty atlernator was the culprit.

Replaced the alternator and checked the voltage and was happy to see 14volts at 2000rpm.

But my daytime running lights didn't come on and my battery warning light stayed on.

So I tested the battery by checking the specific gravity of each cell, only one cell registered fair, the rest registered good. But being a 5 year old battery and grasping at straws i replaced it too. Same thing no daytime running lights and battery warning light stayed on.

So I looked at the negative battery cables and noticed that corosion was permeating into the cable, I cut of 1 inch and still found corosion, so I opted to buy brand new cables. One goes from engine block to battery the other goes from body to battery, both join to a brand new battery connector...same thing no daytime running lights and battery warning light says on.

I have checked the voltage of the battery making sure that the battery doesn't fall below 12 volts after resting a few hours and it is pretty constant around 12.6 volts, and still registers 13.5 - 14.0 volts while running at 1500rpm to 2000rpm.

I'm at a lost as to what is going on.

briefly, one time, right after the new battery was installed did the daytime running lights came on, but the battery warning light has never ceased.

I've checked every fuse in the engine compartment, and a few in the passenger cabin (have some more to check).

what is going on?

Answer
I don't think I can be much help,electrical problems like this are hard enough to diagnose with access to the vehicle to make voltage and resistance measurements using a wiring diagram, whatever it is, it's complicated and not common, not something I can say to, yes I have seen this before and tell you the solution.
To your knowledge has this van been involved in a collision? This would indicate a wire harness problem, possibly high resistance or a short to ground somewhere in the system creating a feedback voltage that keeps the battery warning light on, it could also be one of the daytime running light relays.