SOLVED! Trailblazer not starting please help

[TJBaker57]

It cranks! One of those clips wasn't fully pulled so it wasn't seated. It has a check engine light at run now. Still dont have a fuel pump noise

Great news! Now you can troubleshoot the Fuel Pump issue which might be security related?? Personally, I would start with checking out the fuel pump relay and circuit, much the same way you checked the starter relay circuit. I think you can jump the fuel pump relay at the fusebox the same way you jumpered the starter relay just to prove there is power there and the fuel pump actually works.

 

[MBS1994]

Great news! Now you can troubleshoot the Fuel Pump issue which might be security related?? Personally, I would start with checking out the fuel pump relay and circuit, much the same way you checked the starter relay circuit. I think you can jump the fuel pump relay at the fusebox the same way you jumpered the starter relay just to prove there is power there and the fuel pump actually works.

That man is a saint. I just found that video too. I'm going to watch it and try his tactics to limit it down. Hearing it crank was so relieving!

 

[MBS1994]

It runs! Fuse 10 was blown.

 

[MBS1994]

Okay all in all. Tuned by pcmofnc to erase the VATS, new switch, new starter relay, and blown fuse 10 in the box. Hopefully this helps someone else down the road. Thank you everyone you all are so appreciated! This can be turned to SOLVED!

 

[Blckshdw]

Hopefully it will run reliably for you, for a long time now.

 

[TailBlazerFree]

It cranks! One of those clips wasn't fully pulled so it wasn't seated. It has a check engine light at run now. Still dont have a fuel pump noise

I'm sorry but I don't understand your description of what prevented cranking. One of those clips?

My 2003 TB LTZ is now exactly like your troubles here and I'm desperate.
Ignition switch new, park/neutral switch good, fuses and relay good. Just no ground provided by PCM to the starter relay.

Thanks

 

[MBS1994]

I'm sorry but I don't understand your description of what prevented cranking. One of those clips?

My 2003 TB LTZ is now exactly like your troubles here and I'm desperate.
Ignition switch new, park/neutral switch good, fuses and relay good. Just no ground provided by PCM to the starter relay.

Thanks

Mine was because I sent the pcm and tcm off for a tune. The clips I was referring to are the ends of the wiring harness where they attach to the pcm and tcm. They have a clip on them that when I reinstalled I didn't pull them forward so they weren't fully seated.

 

[JimB]

It should be 12v+ at crank and nothing any other time. What's the red wire showing? It should be 12v+ all the time (BAT). Did you check the 40A IGN A fuse? Not sure if it was already posted but here's the schematic.

Mooseman if I were to run a ground wire from the YEL/BLK wire after starter relay. Will that allow me to continue using my vehicle without any damage or harm to the vehicle?
JimB

 

[TJBaker57]

if I were to run a ground wire from the YEL/BLK wire after starter relay.

I believe doing that would cause the starter to activate all time when the key is in run or start position. Not a good idea

 

[Mooseman]

Yeah, not a good idea. It's the PCM that sends the ground signal through that wire to activate the relay to engage the starter.

 

[JimB]

More information: It is a 2003 Trailblazer, engine very clean, purchased for $2500, previously owned by engineer who regularly changed oil (synthetic), runs great (hesitates a little when when going from idle). I have to pull fuse for instrument cluster to prevent drain overnight (junk yard rebuild installed before i purchased it). I am 58 years old and forced to retire and on fixed income. I was formerly an electrical technician. Not good with electronics. Good with a volt/ohm meter. Only drive vehicle once a month @ 100 miles.
If I jump wire to ground start relay permanently will it damage the PCM or cause me further electronic problems? I or my wife are only ones who drive it and ignition will only be turned to start when starting engine. For the last month I have been jumping around the start relay contact with key in run position and it seems to run and drive fine. I live out in the country in Texas and just need a trip to town once a month. I have done the troubleshooting and believe the problem is in the PCM. Relay does not engage when turned to start.

Thanks for all the help,
JimB

 

[Mooseman]

PCM is rarely, if ever, at fault in these instances. You need to do a full troubleshooting as to why the PCM is not happy by not sending the ground signal. Did you check and/or replace the ignition switch? Are you sure it's the PCM not sending the ground signal and not the positive side that is cut off due to something with the neutral start switch?

This thread is more in line with your issue:
No Crank, Like Attempting To Start In Drive