[CherryHasAPontiac]

Here is the original instructions to install/Replace a starter for my/your 2009 Pontiac g6 3.5L.
I HAVE TO SAY THEY WERE PRETTY VAGUE WHEN IT CAME DOWN TO WHAT WIRE IS WHAT AND/OR WHERE EXACTLY THEY WENT.... SO IF ANY OF YOU COULD HELP ME OUT WITH BETTER ADVICE, I'D APPRECIATE IT! (3 GUYS PRIOR TO MYSELF, FUMBLED AROUND WITH THE STARTER, THE ALTERNATOR, THE BATTERY, AND ALL AND I MEAN ALL OF THE WIRES TO/FROM/ATTACHED TO EACH OF THESE PARTS, BEFORE I KNEW AND STOPPED THEM. NOW I AM ON MY OWN FIXING THE CAR, I HAVE A MESS TO TAKE CARE OF WITH WHAT WIRES ATE WHAT AND WHERE THEY GO. I HAVE WIRING DIAGRAMS, SCHEMATICS, AND GROUND LOCATIONS.......BUT, BUT, BUT, BUT...... I HAD TO Basically REPLACE THE ENTIRE POSITIVE AND NEGATIVE WIRES FOR THE BATTERY, DUE TO THE NEGATIVE HAVING A SLICE/CUT INTO IT ALONG WITH BAD CORROSION IN THE CUT. AND ONE OF THE GUYS CUT OFF MY POSITIVE TERMINAL CONNECTION FOR NO REASON AT ALL. SO IF YOU CAN IMAGINE, LOOSE WIRES DANGLING AROUND, WIRES MISSING COMPLETELY, AND A WIRE THAT IS MOST LIKELY FRIED(THE FUSIBLE LINK). ANOTHER GUY DROPPED MY STARTER AS HE WAS SAYING "YOU GOTTA BE CAREFUL WITH IT" AND BROKE PART OF THE BLACK CAP WHERE THE BOLTS ARE. IVE BEEN ABLE TO REPAIR THAT BUT I JUST CANT FIGURE OUT HOW ITS SUPPOSED TO BE WIRED NOW or what size gauge wire everything is supposed to be. I've pulled and replaced the negative battery cable completely and repaired the terminal connectors for all the wires so that they should be conductive, safe, clean and tight now. But still UNSURE WHETHER OR NOT IF I EVEN HAVE THE RIGHT GAUGE WIRES FOR EVERYTHING AND WHAT IM MISSING. I am REPLACING the FUSIBLE LINK that goes from the starter to the alternator. BUT IT IS ALMOST IMPOSSIBLE to follow it through the harness and reach the end of it to just cut and replace it. So I'm cutting it entirely from the starter and alternator and re-routing it a different way than the harness. Hopefully this works. I cannot find the engine chassis ground that goes to the frame or the car at all. Unsure how many wires I originally had coming from either battery terminals but the car seems to have a terrible grounding problem. The car will start, but stalls and shuts off.

3.5L Engines

1. Disconnect the negative battery cable.
2. Raise the vehicle.
3. Remove the flywheel inspection cover bolts.
4. Remove the flywheel inspection cover.
5. Remove the electrical connections from the starter motor.
   Removing electrical connectors from the starter motor—3.5L engine
6. Remove the starter motor mounting bolts.
7. Remove the starter motor.
   Removing the starter motor—3.5L engine

To install:
CAUTION
Before installing the starter motor to the engine, tighten the nut next to the cap on the solenoid BAT terminal. If this terminal is not tight in the solenoid cap, the cap may be damaged during installation of electrical connections and cause the starter motor to fail later.

1. Install the starter motor to the engine.
2. Install the starter motor mounting bolts and tighten to 30 ft. lbs. (40 Nm).
3. Install the electrical connection to the battery terminal on the solenoid and tighten to 13 ft. lbs. (17 Nm).
4. Install the electrical connections to the S terminal on the solenoid and tighten to 27 inch lbs. (3 Nm).
5. Install the flywheel inspection cover.
6. Install the flywheel inspection cover bolts and tighten to 89 inch lbs. (10 Nm).
7. Lower the vehicle.
8. Connect the negative battery cable.

 

[waterfowler76]

Were you able to figure this out?

 

[CherryHasAPontiac]

No

 

[boomer]

The engine chassis ground runs between the battery ground lug and a bolt that is under the wiring loom in the gap between the air intake tube and the brake fluid. If you look down that gap towards the engine block you should see something like this, where the light is shining and the red arrow points to the ground wire

If it were my problem, I would probably head to a car breakers or pick a part, whatever they are called locally, as I would be able to see / take pictures of the setup and possibly grab the wires you need. However, I do take you point about the wire routing. I decided to double up on the wiring by adding an extra battery ground to both body and engine as well as a fused positive to the alternator. As I was leaving the originals in place I worried less about the gauge, but did add thicker cables for both. Best of luck getting it sorted.