Is it the starter won't engage? If so, first, here is a link you may find helpful:
Now, I attached the wiring schematic below of the starting system. Let's work through this one step at a time.
First, will it start in neutral? If not, go to the starter relay in the under-hood fuse box. There is a yellow wire with a black tracer (pin 86) that receives power from the starter relay/ECM signal. That wire needs power to energize the relay and power the starter. Check that first for power. Also, pin 85 is ground. Confirm continuity to ground.
If those check good, with the relay removed, make sure there is 12v (constant) to pin 30. If there is, place a jumper between pins 30 and 87 to see if the starter engages. If it does, the relay is likely bad. Here is a link explaining how to test a relay:
If it doesn't engage the starter by jumping, you need to check fuse 62 (40 amp) starter fuse after the relay. Remember, a fuse can look good and be good, but it's important to confirm there is power both to and from it.
Let me know what you find or if you have other questions.
See pics below.
Images (Click to enlarge)
Sunday, January 30th, 2022 AT 8:25 PM