Toyota 8FGCU25, battery light on, new battery/alt/cables.

My coworker that has been working on this truck is out of town on vacation so I inherited this thing for the week.

I have to go there today to sort it out.

New battery, new alternator, new cables. The battery light is still on.

Anyone have any idea where to look? My plan is to check the starter and see how far its drawing the battery down while cranking and then if I can run down our only diagnostic scanner, run a test to see what it is saying.

Toyota 8FGCU25, battery light on, new battery/alt/cables.