Will not start

  • 6.2L
  • V8
  • 2WD
  • 140,000 MILES
Checked all fuses, all good to go. Install brand new battery, new pos cable, new ground cable, (had to remove left front tire and inner fender well to remove and install pos and neg cables on this car, while I was under car. I jumper start solenoid, starter turns over. Sent ECM off for trouble shooting, it has comm, got it back and installed. Pulled BCM out, sent it out. Bought refurbished with VIN info flashed into BCM. Now I insert key and turn key to start = no dash lights/no start/no click/noradio/no A/C. The horn works, power door locks work, interior lights work when doors are open and go off when doors are shut, key fob locks and unlocks and truck hatch release works. Going back to recheck fuses and confirm is installed relays back in proper position because 85 and 86 has to have proper placement. Pulling hair out. Please help
Sunday, January 30th, 2022 AT 4:27 AM

1 Reply

  • 108,573 POSTS

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.

Take care,


See pics below.

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Sunday, January 30th, 2022 AT 8:25 PM

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