V1 LeoZug's Montana Street Goblin - '05 Cobalt SS donor

[Rauq]

1. Do you have the clutch switch pressed in?
2. Can you jump the starter to ensure the starter works at all? MAKE SURE THE CAR CAN'T GO ANYWHERE, be 1000% sure it's in neutral with the parking brake on or with the rear end up in the air and super secure, and hit the power and solenoid posts on the starter with a screwdriver or wrench. It should turn the engine over, may spark a little.
3. Key on engine off, do you hear the throttle body move a little on its own? Can you hear, or with the intake tube off see, the throttle body move with the gas pedal?

 

[pisco]

I had a similar problem with "unexplained no crank" It ended up being part of the gmlan circuit. I had left the plug for the mullti function display in case I wanted to use it, I simply had to short the two twisted pair of wires to each other to complete the communication circuit and everything came alive
The next issue is I mixed up the clutch and brake connectors

Make sure you have everything plugged in and to the correct connector

 

[Leo Zugner]

Thanks for these two ideas. I have a friend whos a mechanic and may be able to get him to come over and give me a hand. to answer these ideas specifically:

1. Do you have the clutch switch pressed in? As far as I know, yes. HOWEVER, during the build, one of the videos said to cut a piece of the clutch pedal off so that is would clear the frame or something like that. I did that and got it really nice and cleaned up, but when I got my harness back I found what i believe is a second clutch button/switch. I'm thinking that part of the pedal was actually needed and now I don't have anything to activate that switch? I did however push the switches by hand in different combinations while trying to crank.

2. Can you jump the starter to ensure the starter works at all? MAKE SURE THE CAR CAN'T GO ANYWHERE, be 1000% sure it's in neutral with the parking brake on or with the rear end up in the air and super secure, and hit the power and solenoid posts on the starter with a screwdriver or wrench. It should turn the engine over, may spark a little. This is a step that seems needed and it def a little scary.

3. Key on engine off, do you hear the throttle body move a little on its own? Can you hear, or with the intake tube off see, the throttle body move with the gas pedal? I'll give this a shot too.






I had a similar problem with "unexplained no crank" It ended up being part of the gmlan circuit. I had left the plug for the mullti function display in case I wanted to use it, I simply had to short the two twisted pair of wires to each other to complete the communication circuit and everything came alive. My gauges only have one plug on the back and I dont beleive that I have any other gauge plugs. I do hower have an "ambient light" and "boost gauge" plug that Lonny told me to just tape away and that I don't need them. Could those be part of the issue?

The next issue is I mixed up the clutch and brake connectors. I'll take a look at those and see if that's something.

Make sure you have everything plugged in and to the correct connector. I'll do that. I wish my wiring harness had been labeled better from DF.



Thanks guys.

 

[Rauq]

Step 0 would have been, are you trying to push the clutch all the way in. I tried my first start from outside the car and kicked myself when I realized why the starter worked but the key didn.t

If you're not overlooking that, then next step is to try jumping the starter. No sense in trying to chase wire colors if the starter is dead or not hooked to live power. Make sure you have a thin purple wire on the solenoid post as you did mention having moved things around down there.

If the starter is not dead, check the throttle body movement as previously mentioned. If the throttle body doesn't move, it's probably a GMLAN issue to chase down. I don't have any experience with this. If it does, then we can look at clutch and brake pedal switch wire colors.

No-starts due to the extra display featured in certain LNF/SSTC donors are an issue specific to those donors. You won't have that on an LSJ.

 

[Leo Zugner]

Step 0 would have been, are you trying to push the clutch all the way in. I tried my first start from outside the car and kicked myself when I realized why the starter worked but the key didn.t

If you're not overlooking that, then next step is to try jumping the starter. No sense in trying to chase wire colors if the starter is dead or not hooked to live power. Make sure you have a thin purple wire on the solenoid post as you did mention having moved things around down there.

If the starter is not dead, check the throttle body movement as previously mentioned. If the throttle body doesn't move, it's probably a GMLAN issue to chase down. I don't have any experience with this. If it does, then we can look at clutch and brake pedal switch wire colors.

No-starts due to the extra display featured in certain LNF/SSTC donors are an issue specific to those donors. You won't have that on an LSJ.

Thanks so much! I really appreciate your input.

 

[pisco]

Step 0 would have been, are you trying to push the clutch all the way in. I tried my first start from outside the car and kicked myself when I realized why the starter worked but the key didn.t

If you're not overlooking that, then next step is to try jumping the starter. No sense in trying to chase wire colors if the starter is dead or not hooked to live power. Make sure you have a thin purple wire on the solenoid post as you did mention having moved things around down there.

If the starter is not dead, check the throttle body movement as previously mentioned. If the throttle body doesn't move, it's probably a GMLAN issue to chase down. I don't have any experience with this. If it does, then we can look at clutch and brake pedal switch wire colors.

No-starts due to the extra display featured in certain LNF/SSTC donors are an issue specific to those donors. You won't have that on an LSJ.

I could have been more clear that display issue was an example I specifically had to deal with but any component removed will give the same result if I'm not mistaken the LSJ uses the same communication system. @Rauq please correct this if I am wrong. I was simply trying to state that everything needs to be hooked up.

I agree with and as part of my troubleshooting I did jump the purple wire to crank verifying starter works and has power. Then I started through the list of items that will prevent the pcm from calling for crank.

 

[Leo Zugner]

Hey Guys.

So possible breakthrough. I don't have the purple wire attached to the stud on the starter at about the 2 o'clock position. Hope fully that's it. I'm having a hard time finding it however as the engine is installed and it's super crowded back there. Do you guys know about where it comes out of the engine harness or what plugs may be near it? I'm thinking it's jammed behind something. or if there's a picture of an engine harness laid out? I've been looking for one online with no luck so far.

 

[comegetjoe]

Hey Guys.

So possible breakthrough. I don't have the purple wire attached to the stud on the starter at about the 2 o'clock position. Hope fully that's it. I'm having a hard time finding it however as the engine is installed and it's super crowded back there. Do you guys know about where it comes out of the engine harness or what plugs may be near it? I'm thinking it's jammed behind something. or if there's a picture of an engine harness laid out? I've been looking for one online with no luck so far.

Purple wire is much needed.

 

[Leo Zugner]

Purple wire is much needed.

Yeah seems like it. I found a pic online that seems to show it next to a blue plug. so that's a start.

 

[Robinjo]

Do you have the turn signal switch hooked up? That will also cause a no start condition.

 

[Leo Zugner]

I do have the plug in the stalk. I'm having a hard time getting the blinkers working but my wires aren't labeled so that may be the problem. Does anyone have the blinker wires from the DF main harness identified?

 

[comegetjoe]

I do have the plug in the stalk. I'm having a hard time getting the blinkers working but my wires aren't labeled so that may be the problem. Does anyone have the blinker wires from the DF main harness identified?

Search it up. I just did this a few weeks ago. I believe when I searched @Robinjo ? had posted it up which wire goes where.

Car side Red to yellow mirror
Car side orange to teal mirror
Car side green to white mirror
The spare black wire, maybe not for you, is tapped in here and run up to the Halo headlights to switch from DRL to turnsignal when applied

 

[Leo Zugner]

Ok awesome. Thank you. I have different headlights and blinkers so I’ll try to figure out what’s what.

 

[Leo Zugner]

Ok. So I got the purple wire hooked up to the starter lug but now when I hook up both battery wires the car tries to crank. Even without the key in the ignition. Thoughts? The starter is somehow hooked directly to the battery? Bypassing the solenoid? Sheesh.

 

[Leo Zugner]

Ok so it looked
Like some things were shorted in the starter. Fixed that and the issue is gone. I don’t have crank now but the battery might be dead. I’m charming and I’ll try again tmrw.

 

[comegetjoe]

I’m charming

You sure are

 

[Robinjo]

Ok. So I got the purple wire hooked up to the starter lug but now when I hook up both battery wires the car tries to crank. Even without the key in the ignition. Thoughts? The starter is somehow hooked directly to the battery? Bypassing the solenoid? Sheesh.

It's also pretty easy to get the purple wire ring terminal to touch the main power wires on the starter. I found that out the hard way, engine trying to fire as soon as I touched the positive cable to the battery.

 

[ah.b.normal]

Hey Guys.

So possible breakthrough. I don't have the purple wire attached to the stud on the starter

Purple wire is like "most" important. AND Don't feel bad! I(and everyone else) didn't mention it either! I started noticing that the start wire was Always PURPLE on GM products in the 80's........... I thank you for being forthright and telling us it was not connected! So many times people figure out the problem and discover it could be a little embarrassing and never tell us what fixed it!.......... The next no start on this forum will prolly be met with all of us asking, "Is the purple wire connected to the S post?" That is how all this works! Multo Multo Gratzi!

 

[ah.b.normal]

On an 05 the purple wire is usually a ring terminal that is held on by a small nut and washer, later(07?) changed to a fully insulated plug end and the back of the starter solenoid changed to accept it......... Shorting between that S post and the battery post up top and the starter will spin and engage. (This is a useful way to test a starter and solenoid, by shorting between the two with a screwdriver shaft or other metal object, with the battery + wire connected. The first time you do this you'll jump and so will the starter. Sudden spinning of the guts of the starter motor will flip the motor around on the bench or floor if it is not held down.)....... Ensure there is nothing allowing those two poles to touch. The original battery + wire had a special loop end with a "tooth" on it that stopped this from happening. If you accidentally flipped that end over the tooth does not engage, the + terminal can spin down to touch the S post. OR if you have put a general replacement end on that battery + wire, it can spin when tightened and contact the S post. Just don't let it twist down as you tighten it.

 

[Leo Zugner]

Hey Guys. The advice all worked out. I have crank! I put the alternator wire on first, then the thicker wires. That seemed to keep things nicely in their place.