I have a 2005 yukon xl with 5.3.
Battery, starter, alternator, grounds, connections are good. Starter is getting 12.5v to it. Connections to battery are clean and solid! This started after i put in cheap led license plate lights like an idiot and right after it wouldnt crank at all just clicks but not fast clicks. Swapped out starter relay with one i knew was good and same thing relay clicks. When i turn key the battery starts to get drained quickly. What could putting led license plate lights have done to make it where it wont even crank?? Any solid suggestions are much appreciated!
I think you are confused.
Crap happens, doesn't matter what you did, now was when it decided to quit.
Everyone that suggested the starter would be close but no cigar.
To test the starter you must take it off, take it to advance Auto Parts and they can check it out.
My guess, and it's just a guess is that your ignition switch is bad.
Person that asked about alarm was also a good guess.
Most of those trucks already have remote starter, but aftermarket is a sure fire way to screw up the wiring.
Everything runs off the body control module.
Light amperage draw is monitored by BCM.
When you don't know what you are doing, don't screw with it.
You didn't know what you were doing!
As l tell my 85 year old father, it's not a 55. Chevy.
There are no points plug and condenser.
You can't fix it with a screwdriver, pliers and a socket wrench.
You can throw good money after bad at it or you can take it to the garage.
Drop the panel below the steering column and look at the wiring, jiggle it.
Go to the parts store and buy a ignition switch.
Watch the YouTube video how to install it.
If that doesn't help call a tow truck.
I junked that model of truck 3 years ago, just wasn't worth keeping on life support anymore.