Replaced the GEM Tuesday, no crank and dash not normal. Took a dive into the fuses and relays this afternoon. All the fuses were good but one relay was in the wrong socket and fuse tap was in the wrong place. Getting that in place fixed the dash. Still no crank, remembered about a brake switch potentially causing crank issues. Pulled the emergency brake fully up then the engine would crank but no start. Turned the heater fan off so I could listen for the fuel pump. Not hearing it run. Checked fuse 19 under the hood again and it was good. Looking for suggestions of where to look next.

Thanks.

-Mark

 

Verified that the under hood fuses all have power. Pulled the fuel pump relay and tried using a jump wire between power and load.

 

Tested the relay socket again. Pin 30 has power constantly, Pin 85 has no power, When key on it has no power. Pin 86 has no power, When on it has now power. Pin 87 is the N/O load side.
When attaching jumper between 30 and 87 there is a spark indicating a power draw. When the engine cranks it will not start,

These symptom lead me to believe there is some thing up stream on the activation circuit of the relay not functioning.

The inertia switch has not been tripped.

 

Ran ForScan on the truck,

It found the OBDII, PCM, GEM. ABS
DTC errors reported for PCM, GEM, & ABS.

Pulling the power to the battery for 15 minutes.

 

After reconnecting power, the ForScan will not see the truck.

Adapter: ELM327 v1.5
Unable to connect to vehicle.