Alternator not engaging

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Jan 10, 2021 | 01:58 PM

Andrew

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Drifting

Joined: Aug 2000

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From: Jefferson City MO

Alternator not engaging

Posting this for a friend who has a 2008 z06 that just got a RHS implant and big blower with supporting mods. Anyway, the alternator is not charging. Took the alternator to get tested and it failed. So, purchased a new alternator from GM. However, same issue. Checked and it is getting the "start" signal and has 12v. The status of the third wire running to the ecm is unknown. Any advice? ECM? Could the tune to get the car moving before dyno have the alternator turned off?

To check the third wire might need a gm tech 2. Any advice on the best place to get one at a reasonable cost?

Thanks everyone!

Jan 10, 2021 | 02:02 PM

Chris_G

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Joined: Nov 1999

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From: NOVA

St. Jude Donor '05-'06-'07

Quote:

Originally Posted by Andrew

C-6 seems to be picky with alternators. I hate to ask the obvious but was the new alternator tested off the car like the old one?

Jan 10, 2021 | 04:31 PM

C5 Diag

Moderator, Tech Contributor

Joined: Sep 2013

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From: Cape Coral, Florida

On my C5 the gray (F Terminal) at idle (no load)

reads 73.7 Hz, 2.27 volts, and 71.3 duty cycle as you can see.

Jan 10, 2021 | 08:51 PM

wjnjr

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From: Klein TX

2023 C6 of the Year Finalist - Unmodified

2022 C6 of the Year Finalist - Unmodified

Jan 10, 2021 | 10:11 PM

Andrew

Thread Starter

Drifting

Joined: Aug 2000

Posts: 1,601

Likes: 52

From: Jefferson City MO

Thanks for the input! Yes, the new alt is good. I have no idea what volts, htz or duty cycle is on the c wire. Will have him check and post.

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