Ive been working on my car since October and I finally got to the point where I can start it and no joy. Ive done a ton of electrical over the winter, including:
Relocated wiring under the hood(required cutting and extending 40 or so wires off the main harness)
Relocated battery to the rear

Battery is connected to a kill switch with 0 gauge, as well as the alternator. I have the starter and fuse boxes going 2 gauge each to an 0 gauge back to the kill switch. Battery ground is an 0 gauge as well as the engine ground.

Heres whats going on, interior lights, headlights, wiper, PW, PL, gauges, and fog lights are all working fine. When I go to put the car in the RUN position, the fuel pumps dont prime, and when I tried to start it the starter solenoid isnt engaging at all. I troubleshot the fuel pumps by hook the trigger wire directly to the battery and they primed fine so the issue lies with the trigger wire elsewhere. The most troubling part is that when I hook my HP Tuners up it cant locate the computer. Its almost acting like there is a blown ignition fuse. Looking in the fuse boxes theres several options I can trace:
ABS IGN(no fuse in here, I got rid of the ABS over the winter)
ENG CNTRL(No idea what this is but theres a fuse and its wired in still)
PCM IGN(I feel this is a likely candidate for being the main issue)
IGN(Looks like a large relay?)
ABS BAT SOL(?, no fuse)
TCS BAT(?)
PCM BAT(Fused and wired)
ABS BAT 1 and 2(?)

No blown fuses anywhere, all of the ABS and TCS ones are not in use any longer and I have pulled the fuses. I feel this has to be an ignition/PCM related issue as electrical is working on the majority of things, just not the ones that I need to start the car I truly feel it is not the wire relocation because I labeled both ends of the wires prior to cutting them and verify before reconnecting them.

Can someone point me in the right direction?

I suppose I should pick up a mulitmeter and learn to use it LOL

 

Swap the fan 2 relay and the ignition relay and give it a shot. If it fires up then you need a new ignition relay

 

Are these the gray blocks in the fuse box up front? If so, I tried that after I posted last night.

Is there any other relays on this car I should be looking at? I find it odd that the fuel pump isnt priming, the starter solenoid isnt engaging and the PCM isnt being seen by my HP Tuners. Is there a common denominator?

 

Oh man, i feel for you! I hate electrical issues. What about grounds?

 

I count 3 grounds coming off of the wiring harness. Pulled them off last night and verified it was solid metal on metal contact. Engine ground looks good also but I suppose I could double check it.

Just combed through some diagrams and the common denominator between the fuel pumps and the starter is the BCM, but I havent touched that at all. Here are the diagrams I found:

 

Woah, big pics. Sorry.

 

If the fuel pump doesn't prime I don't think it's the ignition relay. IIRC, it primes when this is bad. I'd try it, but my ****'s all apart.

Looks like the BCM could have something to do with it. I'm not sure though. If you know anyone that can swap it over to see I'd try that.

 

May way of thinking says if the ignition relay doesnt kick on, it doesnt activate the PCM. Having a hard time finding an ignition schematic to verify this. Im grabbing a multimeter after work and going to town. I watched some YouTube videos so I should be an expert at it right? LOL

 

yup

 

The OBI 2 port should read no matter if the ignition is on or off.... I would try the fuseable links that where for your ABS. I'm thinking that the ABS ignition? Knowing GM they probaldly thought it was wise to wire it into the main ignition so no one can disable it for cause of harm or death.

 

Good news, I jumped the PCM IGN wire with a known good power source and my fuel pumps began to prime, huzzah! Looks like its just the PCM IGN wire that isnt getting power. Bad news, I have no idea where it leads. It goes up the main harness to the cabin so I guess thats my next stop. I checked voltage just before my wire extension and no reading there either. So either I have managed to cross up a couple large(12 gauge or so) pink wires or there may be a burned out relay further up the chain. I need to pull a diagram for the PCM now.

If nothing else, I can wire in a relay from a known good "key on" wire and make it work that way. Ill try to trace it first.

 

do you have all the wiring diagrams for the car?

 

I only have fuel and starter, as well as the pin outs on the PCM. If anyone had the diagram that has the PCM IGN relay, I think it might be power distribution.

 

So Ive traced this wire to the point that I would need to take the dash apart to look any further. Im just going to go ahead and make another power wire. Do you think it would be ok to splice into the existing ignition wire for power? Looks to be 10. maybe 12, gauge so it should be fine amperage wise. Other than that I cant think of anything to do, short of running a new power wire back to the battery, which seems silly.

I was thinking it was a ground issue with the PCM but I remember when I jumped the PCM ignition wire from another power source and it came to life. If there was a bad ground it wouldnt have completed the circuit right?

 

Havent had much time to work on this but I worked on some of the wiring tonight. The PCM ignition works just fine when I jump it from another power wire, Ill get that fixed later. The 2nd issue is the clutch pedal position sensor is not working. The purple wire gets 12v when I turn the key but the green wire gets nothing through it when the pedal is pushed in and the key is turned.. I disconnected the connector from the sensor and jumped a wire from the purple to green. I checked further down the line and the green is getting 12v when the key is turned when I do this. Looks like I need a new CPP sensor. I guess its been 11 years and a whole 45k miles, do these go out very often?

To make sure there were no power or ground issues at the starter, I jumped a wire from a different power source to the positive wire at the starter(facing the starter) and the actuator kicks on.

 

what's the verdict? you going to have this thing fired up or what?

I really hope I don't have these issues when my car gets back together. what type of connection did you use on the wire extensions?

 

Replaced the clutch pedal position sensor and now the green wire to the starter relay is getting power. Still cant get the starter to work.

On the starter relay:
Purple(ground) is showing good continuity
Yellow/black(wire to BCM) is showing good voltage when the key is turned
Red(positive) is showing good voltage and is always on
Green(wire to pedal position sensor) is getting good voltage.

I guess Ill start checking at the starter..

On a good note, my HP Tuners can read the PCM again so atleast I can assume that isnt fried or something stupid

 

Issue is fixed. The yellow/black wire from the underhood starter relay to the BCM is not grounding at the BCM so it was not completing the circuit and activating the really. Temporary fix; put a ring terminal on it and ground it to the frame. Im assuming its some kind of bullshit microcrack in one of the solder joints of the BCM because everything else that is hooked to the BCM is functioning fine.