Is there any way I can test the computer on my truck to see if it is working or not? Here's a list of things that do not work on my truck:
Overdrive
Downshift
Alternator(works now b/c Ihad an internal regulator installed)
Cruise control
Radio

I need to get this truck shifting into o/d badly bc I do a good bit of hwy driving, any help is appreciated, thanks

 

with those items out, it's a pretty good bet the pcm is gone.

But I don't remember the pcm controlling the radio

 

It sounds to me more like the crank sensor is to blame. Check the crank sensor gap and the wires to the sensor - especially where they come around the front of the head.

 

How do I test the crank sensor? Spacing etc?

 

Inspect the wiring, the gap should be 0.050". Use a non-ferrous feeler gauge. In a pinch, a matchbook cover folded in half is close enough.

 

I wonder if I should disable my internal regulator in the alt. Before I do all this