Hmm. Not sure. The power feed goes from the battery, to the starter, then to the alternator.
Guess you could have a dead short at the end of that feed but I doubt that's the problem. The OP said the battery checked out OK, so I think the battery would show a problem because it would have been dead shorted too.

 

My thought game is: the alternator has an internal short (maybe at the on signal wire) so when the engine is off the battery does not see it, when the key goes to "on" the signal is sent to the alternator and the starter causing the dimming of lights and no crank.

Remembering the alternator is a motor that needs to be turned on. That's what the small gauge wires in the plug are.

 

But,then something as stupid as somebody installing an LED incorrectly could do the same thing.

Most people think an LED is just a tiny light bulb, not a switch that glows when closed.

 

Might be interesting to see if there is a big voltage drop at the battery when the key is activated. That would kinda point to a short somewhere in the circuit.

 

I just realized that nobody has thought of the hood ajar switch. Cars with remote start will not crank if the hood is open or the switch is bad.

 

I want to thank everyone for their input. I'm driving out to look at the car tomorrow morning. I will checkout everything y'all gave input on. I will report back sometime tomorrow, hopefully with some good news. Thanks again everyone.

 

Here's the update:

I did not travel to my brother's yesterday because it was raining all day. I came this morning to continue trouble shooting. I checked all the grounds on the vehicle, all looked good and had no excessive resistance to the chassis.

I completely took apart the fuse box and cleaned all contacts. I inspected all the wiring and ensured there were no broken leads or anything funky.

The vehicle does not have a check engine light but I decided to check for error codes anyway. I get the following error code:

"U0100 Lost communication with ECM/PCM 'A'"

I also verified that when the key is turned, there is power going into pin "86" of the crank relay. However, there is only 1.95V going into this pin, not sure how much it needs to energize the relay. There is no voltage at the solenoid terminal of the starter when the key is turned.

Any inputs?

 

The connectors to the ECM may have bent pins. Did somebody disconnect them just before this problem?

That code is the problem, but it is not easy to find the point of failure.

THE question is what happened immediately before the problem started.

This link will help:
http://www.obd-codes.com/u0100

 

No one's disconnected the ECM. My brother says that he would have to attempt cranking multiple times before the car would start. Sometimes he'd go to start the car and it would not start displaying the same symptoms it's displaying now.

 

check for frayed or broken wires at the ECM connection