2005-2007 Corvette alternator output voltage is low
10-02-2012, 10:05 PM
#1
2005-2007 Corvette alternator output voltage is low Moderators, I originally posted this in the Generation III External Engine section, but in hindsight wished I had posted it here. Please move the original post if you'd like.
I am finishing up installing a LS2/4l70e out of 2008 TBSS with a new C6 (2005-2007) Corvette accessory drive into a 69 Camaro. When the motor is running the alternator output is 11.6V at the alternator and slightly higher at the battery. After the motor runs for 10-15 minutes the voltage output at the alternator and battery steadily decline.
Exciter wire - I soldered in a 470 ohm resistor inline on the red exciter wire in my harness going to the alt plug.
Grounds - I have two 2/0 cables going from the engine to the body, the engine harness is grounded directly to the body and the trunk mounted battery has a 2/0 cable grounded to the body.
Even though the alternator is new I may have it bench check , but first does anyone have any suggestions?
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I am finishing up installing a LS2/4l70e out of 2008 TBSS with a new C6 (2005-2007) Corvette accessory drive into a 69 Camaro. When the motor is running the alternator output is 11.6V at the alternator and slightly higher at the battery. After the motor runs for 10-15 minutes the voltage output at the alternator and battery steadily decline.
Exciter wire - I soldered in a 470 ohm resistor inline on the red exciter wire in my harness going to the alt plug.
Grounds - I have two 2/0 cables going from the engine to the body, the engine harness is grounded directly to the body and the trunk mounted battery has a 2/0 cable grounded to the body.
Even though the alternator is new I may have it bench check , but first does anyone have any suggestions?
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10-03-2012, 06:02 AM
#3
Well this is a lesson in humility. I check the resistance on the exciter wire and noticed I had 900 ohm resistance. I removed my 470 ohm resistor and the reading drop to 400 ohm. I reconnected the wire, started the motor and like magic the alternator output jumped to 13.2v and measured 12.7v at the battery.
When I originally got my harness from SSP Wiring, they did not label any of the wires like they said they would and they never replied to my emails about the hooking up the alternator exciter wire. I was so enamored with the fact I read I needed a 470 ohm resistor I did not check to see that they had already done this......
When I originally got my harness from SSP Wiring, they did not label any of the wires like they said they would and they never replied to my emails about the hooking up the alternator exciter wire. I was so enamored with the fact I read I needed a 470 ohm resistor I did not check to see that they had already done this......
