2008 Suburban won’t start
Did the motor turn over before the replacement was done? If yes, I'd be checking all the wire harness connectors that got moved, tugged, and forgotten while you were working on the replacement. Make sure all the relays in the fuse block are tight in their sockets. Is the RUN/CRNK relay working? It should click when you turn the ignition switch to RUN.
I'd be looking for a wiring diagram. Let me get this correct. Your starter _will_ engage using the relay, but the motor still will _not_ continue to operate with the key in the ON position?
Starter will engage with the relay, but motor will not start/run.
I'm going by my 2011 diagrams for the following info....
"No click"...
Re-Check the DLIS #35 fuse, it supplies power to the ignition switch and then the RUN/CRNK relay.
No BCM needed for the RUN/CRNK relay to energize.
Check to see if 12V is on that fuse socket. If not, there's something wrong with the fuse block.
If you have 12V on both sides of the fuse, check for power on the RUN/CRNK relay coil socket (Pin 86?) with the ignition switch in the run position.
Check the other relay coil socket (pin 85?) for continuity to ground. A bad ground could be your problem!!
And, there should be power on one side of the relay contact all the time. Pin 30 on my diagram.
If everything checks, give the relay a rap or two to see if it's stuck.
Wiring description...
DLIS Fuse to Fuse Block Connector-X5 Pin-D1, RD/WH wire to Ignition switch
From Ignition switch, YE wire, Fuse Block Connector-X5 Pin-H5 to RUN/CRNK relay coil (pin 86?).
RUN/CRNK relay coil (pin 85?) to Fuse Block Connector-X2 Pin-N5, BK wire to GROUND.
The STRTR relay is energized by the ECM via the BCM via the ignition switch (crank position).
The ECM gets power from the RUN/CRNK relay.
>>>> The RUN/CRNK and the STRTR relay share the same ground connection. <<<<
Without the RUN/CRNK relay working, the STRTR relay will not energize (NO Crank)
The ECM gets power from the RUN/CRNK relay.
>>>> The RUN/CRNK and the STRTR relay share the same ground connection. <<<<
Without the RUN/CRNK relay working, the STRTR relay will not energize (NO Crank)
The STRTR relay is energized by the ECM via the BCM via the ignition switch (crank position).
The ECM gets power from the RUN/CRNK relay.
>>>> The RUN/CRNK and the STRTR relay share the same ground connection. <<<<
Without the RUN/CRNK relay working, the STRTR relay will not energize (NO Crank)
The ECM gets power from the RUN/CRNK relay.
>>>> The RUN/CRNK and the STRTR relay share the same ground connection. <<<<
Without the RUN/CRNK relay working, the STRTR relay will not energize (NO Crank)
RUN/CRNK relay has power...no ground
STRTR relay has power. Has ground - Same ground?
There is no yellow wire at the ignition switch. Unlike every wire diagram I’ve seen.
Last edited by Nattydrd81; Nov 2, 2019 at 2:41 PM.





