I need some no crank no start help,please!

[L8NiTe]

Ok i have a 2002 chevy tahoe z71 4wd 5.3.I bought it and was told the starter was going out that sometimes it would start and sometimes it wouldnt,so the guy showed me how he got it started with a screw driver being stuck onto the starter b+ post and trigger wire post.Worked fine but who wants to do that?So i bought a starter from autozone,paid to have it installed thinking i couldnt do it.When it was done the truck started maybe 10 times in a row within a minute.I just turned it off and on to make sure it lept starting,then i went in for the night thinking it was fixed.I came out the next morning and.....no crank when i turned the key.
So the first thing i did was go buy a brand new 300 dollar craftsman mechanic tool set,a multi meter and a test light.I took the starter out myself(was super easy dont know why a backyard mechanic charged me 100 to swap it before for a 10 minute job) took it back to auto zone and had it tested,tested out to be working normal.So i came back home reinstalled it tried to crank again and nothing.So i moved on to connections,i replaced with 1/0 power wire,the Power from battery to the fusebox under the hood,the power from the battery to the alternator,the power from the battery to the starter,the ground from the battery that goes up near the fog lights(but i didnt ground it to the same place i used a clean body bolt near the battery that connects that little metal bar that goes caddy corner across the top of the battery location.I then found there was a grounding strap on the driver side firewall that connects to the engine block im guessing,tugged on it seemed connected good,wasnt all green just looked a little dirty,i un did the bolt connecting it to the fire wall and cleaned it a bit then put it back on.Then i found out there was another ground on the passenger side rear of the motor,the persons video i watched it was a single small ground wire,but on mine it was a pair of the same 2 wires going from the back of the motor into wire loom behind the plastic vortec intake cover.I cut those wires,and ran a new wire from the end of them to the ground the ground strap wire is on on the opposite side.Tried to start it,still no crank.I probed IGN fuses in all locations with a test light to make sure power was getting to both sides of the fuses and they all seemed to be fine.I swapped some of the big relays around that were the same as others in the big fuse block under the hood,made no difference.The last thing i did was put in a whole new ignition switch with the harness on it.Still nothing.Im just getting so aggrevated with everything and im lost.The only other 2 things i have read could cause a no crank issue was the crankshaft position sensor or the neutral safety switch.I have a brand new optima yellow top battery that tests out fine with the multi meter.

IS there anything im missing?Has anyone else had this problem and done all ive done only to find out it was something else.Im losing my mind.I went into this knowing only basics about repairing things on a car,now i feel like i can tell you most stuff about a ignition circuit to the starter lol.I dont mind the fact i learned all of this and know how to work on those things now,im mad because ive done all of that and its still not starting.I can still turn the key to on,and start the truck with a screw driver in the starter.Sorry for the super long post i just wanted to explain everything ive done to save time with back and fourths.

 

[corvette744]

So get a test light touch the small terminal on the starter with your test light while someone turns your ignition over to try and start it.Obviously ground the other end of your test light does the light light up-im assuming not.That is step 1 of starter solving.If it lights everything to your starter is good meaning power and ignition.I think the starter grounds itself thru the block with the bolts or has a ground strap like you said.Seeing how it starts if you jump the wires sound like grounds are good and your not getting power to the small wire on the solenoid.Check that and let us know.Some vehicles that small wire is a fusible link and burns thru if shorted?? Or neutral safety switch.1 more thing do you have an aftermarket alarm system on the tahoe.I applaud you for going this far most would of taken it in again.

 

[L8NiTe]

Im not gonna give up.I get frustrated but i know thats part of the game and why it cost so much to have the work done for you.
I will test the small wire on the starter as soon as the wife can walk out and help me.I have a multimeter as well if that would be better than just the test light.
I did not do any key relearn procedure,i seen it said on some site that may need to be done after changing batteries,changing ignition switch or the BCM.I was just out there putting a new heater hose T on since i snapped the old one when messing with the engine block ground.I got in the truck and turned the key about 10 times and it magicly fired right up and ran fine.I turned it off and tried to fire it up again and nothing same ole single click at the fuseblock inside the truck when i tried to start it.Ill get that starter switch wire checked out and report back thanks.

 

[HiHoeSilver]

If nothing else, you learned a good trick for starting a car with anything metal if need be. Keep us posted.

 

[Scottydoggs]

the ground cable could be shot. the wiggle can make em work for a short time. if you see bare copper at either end of the ground replace it. its likely got dry wire and is no longer a good ground.

you can also run another ground cable engine to battery, this way you know the engine is fully grounded. as the starter has no ground, bolting it to the engine is its ground.

you'll need to change the battery bolt in the stock cable to add another cable. one like this works. that pic the plastic shield is off the cable, you push out the stock bolt and push this new one on its place.

 

[L8NiTe]

Ok i just checked the starter switch wire while the wife held the key in crank position and the light didnt light up.The main battery wire to the starter lit up no problem.

 

[L8NiTe]

Would anyone know where that switch wire runs to?I can run a wire from the starter right to where the switch wire connects in the relay box(im guessing) and if it cranks that should tell me the original starter switch wire has a bad connection somewhere,i then can permanantly run a new fresh wire from the starter to that relay im guessing it goes to and solve that problem....am i correct in thinking this?

 

[corvette744]

Ok i just checked the starter switch wire while the wife held the key in crank position and the light didnt light up.The main battery wire to the starter lit up no problem.

Ok so next have the wife get back in and hold the key in the run position while you check the crank fuse a 10 amp fuse.I check with a test light because of the sharp tip on it so you dont have to remove it and add jumper wires.If the light lights up while she is holding the key to run the ignition switch to the fuse is all good.Let us know after that.Make sure to test both sides of the fuse.You are narrowing it down now.Check all your fuses i think their are 2 for the ignition circut-and i would take the starter relay out after testing everything listed first.You can switch the relay with any other with the same number on top i believe and see if the relay is bad or corroded.If you get this far you will have figured it out Because after the relay its just the wire that runs to the starter.

 

[Scottydoggs]

that wire it triggered by the key being turned to crank, so somewhere between the starter and the key it might be damaged.

if you ever wanted to do a push button start, oh boy nows the time.

all you need to do is run a new wire off that little starter stud to a powered switch and shes cranking over. run the power from a ignition on aka (key on only ) circuit. so you key in and turn to run, then push the new starter button and she fires up.

 

[L8NiTe]

Ok so next have the wife get back in and hold the key in the run position while you check the crank fuse a 10 amp fuse.I check with a test light because of the sharp tip on it so you dont have to remove it and add jumper wires.If the light lights up while she is holding the key to run the ignition switch to the fuse is all good.Let us know after that.Make sure to test both sides of the fuse.You are narrowing it down now.Check all your fuses i think their are 2 for the ignition circut-and i would take the starter realy out after testing everything listed first.You can switch the realy with any other with the same number on top i believe and see if the relay is bad or corroded.

Is that fuse in the box under the hood or in the one on the driver side of the dash?