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Discussion Starter #1
Yesterday I was driving in my G8 and hit a bump and car just turned off, tried turning it back on and I get nothing, not even a crank, lights work, battery is good, it will crank if I engage the crank relay manually but it won’t crank with the key....please if anyone can help!
 

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If what you did was jump pins 30 to 87 of the crank relay (to eliminate the starter an some of the electrical circuit, then try this. >>>>> To eliminate as much as possible (with the easy to T/S stuff) have a multi-meter at the ready. Start by reversing the R8 defog relay (just above the R12 start crank relay), and try again with the ignition key an the transmission in either the PARKED or NEUTRAL position. If no joy, remove the crank relay an verify you have continuity from pin 85 to a good ground source. If OK, set meter up to see if you have about 12 volts from pin 86 to a good ground source while a helper rotates the ignition key to the start position an holds long enough for to to see if the voltage shows up (again with the gearbox in parked or neutral position). If no power available, your now into some heavy (hope you don't reach this point) electrical problem.
 

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09 G8 GT Owner
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128 Posts
All of a sudden I'm also suffering with a no crank situation at 98k miles. Our G8 GT is stranded at my wife's work. Before finding this thread, I had already reversed the defog and crank relays to no avail. I don't know the pin #'s but I tried to jump across randomly with a paperclip. First attempt it just sparked. When I tried a different jump the clip became molten hot instantly and burned my fingers badly, yet still no crank. I'm out of ideas.

I had both keys in the car to assure it wasn't a transponder issue.
 

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Reads like you jumped the hot battery buss pin 30 to the ground pin 85 (which is going straight to ground) on that relay receptacle. That would turn that paperclip into a quick heating element. Once you figure out the pin # layout on the R12 relay base (an with the ignition turned off), you need to jump pins 30 to 87. That will simulate the relay being energized (as it would be), with the ignition key rotated to the start position. If if cranks correctly, you can at least eliminate the start/crank motor.
 

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09 G8 GT Owner
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128 Posts
Jumping pins 30 to 87 netted a solid spark but still no crank. I now suspect a starter solenoid issue.
 

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I would have to agree on that call. Thinking that the starter an its solenoid being located in a hard to get to location (along with a heat shield probably wrapped around it), the chances of thumping that solenoid with a smacking device (to get it to free up) an allow you to get it started one more time, are kind of slim. It *would* be nice to get that car to a friendly location for the fix.
 

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09 G8 GT Owner
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128 Posts
Had no luck hitting the starter with a hammer. I verified I have the earlier starter but the later starter is more affordable and more readily available. Will it retrofit?
 

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09 G8 GT Owner
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128 Posts
The death of my Pontiac G8 GT starter(6.0L V8). If you look closely you'll notice the heavy cable between the solenoid and starter motor has melted apart. New starter cured all issues.

 

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09 G8 GT Owner
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128 Posts
I believe an "external meltdown" is an appropriate explanation. Our 98k mile G8 gets driven through serious snow every winter in the Poconos and sadly the extensive use of road salt is terrible for the underpinnings of our beloved Pontiac. But... it's an absolute HOOT to drive in the snow!!
 

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At least a resolution was relatively cheap and easy. Supposedly, here they use a chemical far worse than salt to prevent ice accumulation on roads. AAA says undercarriage repairs cost consumers billions of dollars every year. Try to hose off/down the undercarriage once the winter months subside, but would imagine things are quite different in other parts of the country.
 
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