help, 6.4 no start no crank

[krasselt21]

I am having an issue with my 6.4, everything works in the dash, but I get no fuel pump or no crank when I go to turn it over with the key. no theft light. I un plug connector by passenger battery and it turns over. would this be fuse or relay issue? or bad ecu? can you test ecu?
I'm going to start checking fuses and relays tonight just looking for some other advice
issue just started a couple weeks back.

 

[krasselt21]

i was able to cycle the key a couple times and then it would start. now it does nothing. get code that says it lost communication to ecu.

 

[sootie]

have you checked the inertia switch?

 

[krasselt21]

would that cause a dead key,
I haven't checked that yet, I was out of town when this happened. going to start checking stuff tonight.

 

[sootie]

not totally sure. is the pats light blinking on the dash?

 

[BOSS450]

Inertia switch will cause a dead key until you reset the codes. Check that first. Passenger side right inside the door.

 

[krasselt21]

security light is not blinking.
everything works, just wont crank or kick fuel pump in. I can tell if its going to start as soon as I hear the air dog kick in.

 

[BOSS450]

Well that's the only reason other then faulty wiring it won't start. A 6.4 will crank without a lpfp running btw. So check the inertia switch first

 

[krasselt21]

I did have it crank and crank and not start, but then I would cycle key and hear air dog then it would start. hopefully that is it. I will check that if not I am down to checking relays/fuses/wiring

 

[dohcter]

Check the factory fuel pump harness connector as it enters the main chassis harness. i had one the other day where the pin was corroded out of the connector, no pump, no crank..