03 Yukon won't crank random indicator lights

[Cassabaum]

I have a 2003 Yukon XL 5.3L that has normal indicator lights with ignition switch in the ON position. When turned to the START position, nothing happens (no click - nothing). The shift position indicator does not show what position it is in (the P, R, D, etc are lit, but not underline showing position). When ignition switch is turned off and key removed, the E-brake light, seat belt, and security lights all stay lit. Rear wiper randomly changes position.

Trouble-shooting steps we have taken:
1) Battery voltage was low (10.5) and would not hold a charge - battery old and probably stressed during trouble-shooting
2) Replaced battery, cleaned and checked all cables and connections (ground lugs) to frame and engine. Check all fuses (both engine compartment and interior). Checked for frayed, loose, or broken wires
3) Symptoms did not change
4) Measured supply (battery and ignition voltages) and grounds checked at Body Control Module (BCM)
5) Replaced BCM
6) Symptoms did not change

Seems not starting could be related to shift indicator not working, i.e. the system can't verify that it is in Park or Neutral to allow it to start. But, how does the fact that the indicator lights (i.e. E-brake, seat belt) related to the fact the system doesn't know what gear it is in??

We are stumped .... any ideas for additional trouble-shooting steps would be greatly appreciated!!

 

[Korkay Cleaning]

Starter Relay

I have a 2003 Chevy Tahoe and had a similar problem. What I found was the starter relay was not seated properly in the fuse block. i pulled the relay and switched it with the tail light relay (right next to the starter relay) and the truck started right up. i switched the two relays back to their original positions and everything still worked fine. I took one of my wife's emery boards and cleaned the terminals and spade receiver int he block and have not had a problem since.

 

[TxDrewski]

Fuel Pump may be blowing a Fuse. That is EXACTLY what happened to me less than a month ago.

---------- Post added at 07:07 PM ---------- Previous post was at 06:58 PM ----------

To elaborate..
My truck died in the middle of a turning lane at 5pm, in traffic. I could turn my key and nothing would happen, wouldnt turn over, no click, no nada.Checked fuses and there was a blown ignition fuse, 20 amp I think. Replaced it, and turned the key, blew again...and again..and again... Got online and found out that was a symptom of the fuel pump failing. Changed the pump, no issues now.

 

[RCB]

Did you check the inhibitor switch?