No crank problem

25074

25074

Member
Ok…let me try to explain

my donor is an 06 2.4 SS. Non SC or TC.

I thinned my own harness. I have everything ready to start the car so I am done with stage 1 stuff.

when I turn the key, the butterfly activates but no crank and the dash lights up

I have power to everything so it’s not a ground issue.

I have power to the relay that activates the starter but the Starter will not turn.

my test light shows power coming out of the output side of the relay terminal in the fuse box and it would stay lit once you let go of the key (I assume this is the cars way of continuing to crank to start the car and would stop once it was running)

I can jump the purple wire from the battery and the starter cranks.

I tested the relay with a 12v power supply and it clicks.

if I jump the terminals where the relays sits in tjethe starter cranks.

I have continuity from the relay terminals down to the purple wire at the Starter.

I think it’s an anti theft issue, but the light is NOT activated on the dash.

the car ran fine when I striped it.

I have continuity between the data wires at the OBD

PLEASE HELP ME!!!
 
G

Gtstorey

Goblin Guru
I’m having trouble following where you are losing the 12v start signal. Are you getting the 12v start at the starter, purple wire?
 
G

Gtstorey

Goblin Guru
Don’t get overwhelmed, take things one at a time. Find the wiring diagram for your model and start tracing things all of the way through.
 
G

Gtstorey

Goblin Guru
So back up one step. Are you getting 12v on the purple wire as it leaves the fuse box? I don’t have the wiring diagram for your model but it’s connector x1 wire b10 on the later models.
 
25074

25074

Member
When I put 12 volts to the relay on the bench, I can hear it click.
But when I turn the key, it doesn’t click
 
25074

25074

Member
I do NOT get 12 v at the purple wire unless I take the relay out and jump the switch that way.

it sounds like a bad relay, but when I switch it with the other relay that controls the butterfly (same number on the relay) it operates the butterfly and the butterfly relay still does not click or crank
 
Ross

Ross

Goblin Guru
Is it a safety thing? Clutch pressed in, switch working? Or if it is an automatic, in Park?
 
Ross

Ross

Goblin Guru
I have had this issue when data is not flowing on the GM LAN. When this issue occurs, if I turn the key to the run position, use the purple wire to start the engine, it runs. Then I might have power steering, might not. Same with the instrument cluster. Just depends how far the data is flowing.
 
25074

25074

Member
How do I solve that? I have continuity from the obd to the engine connector through both data wires.
 
Ross

Ross

Goblin Guru
I don't think the power steering works with the engine off... but I would have to test that.
I have been fighting the data flow issue for a few years. It is intermittent, so it becomes much harder to find.
Have you reseated the power blocks in the fusebox and BCM? Loosen the 7mm bolts, and re-torque them down.
 
Ross

Ross

Goblin Guru
Check the resistance across the GM high speed LAN. Should be 60 ohms, if both 120 ohm resistors are in place. (pins 6 & 14)
Maybe other threads like this one will give us ideas.
29329
 
G

Gtstorey

Goblin Guru
Are you getting continuity to ground on terminal 85 of the relay, x1-b12 black with white wire? Full time 12v coming from the crank fuse? 12v feeding the crank relay? You first post made it sound like you had power coming from the crank relay but know you don’t?
 
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