1985 C4 displaying high voltage
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2nd Gear
Joined: Sep 2022
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1985 C4 displaying high voltage
Hello. I am a new forum member. Thanks in advance for any advice.
I recently purchased a 1985 Corvette. The car is in really nice shape with 43K miles. Recently the dash indicates that the car is putting out 16.4 +/- Volts. With the car running I have measured 14.3 volts at the battery and 14.5 coming off the alternator but the dash is telling me 16.4.
I have swapped out the alternator and the battery - still the same. Checked many grounding spots and they all seem tight and clean.
When I turn on all the power accessories, particularly the rear defroster, the voltage goes down enough for the red light to go off. Sometimes the voltage will just go down to 14.5 by itself and stay there. I appreciate any thoughts.
New 9/8/22: I noticed something today. With the voltmeter reading 16.8 at the dash, I put the rear defroster on and the voltage dropped to a safe range but the dash lights also became very dim, almost off. Turn the defroster off and the dash lights back up and the voltage indicator goes back into the red at 16.4 + volts.
giammarco is online now
I recently purchased a 1985 Corvette. The car is in really nice shape with 43K miles. Recently the dash indicates that the car is putting out 16.4 +/- Volts. With the car running I have measured 14.3 volts at the battery and 14.5 coming off the alternator but the dash is telling me 16.4.
I have swapped out the alternator and the battery - still the same. Checked many grounding spots and they all seem tight and clean.
When I turn on all the power accessories, particularly the rear defroster, the voltage goes down enough for the red light to go off. Sometimes the voltage will just go down to 14.5 by itself and stay there. I appreciate any thoughts.
New 9/8/22: I noticed something today. With the voltmeter reading 16.8 at the dash, I put the rear defroster on and the voltage dropped to a safe range but the dash lights also became very dim, almost off. Turn the defroster off and the dash lights back up and the voltage indicator goes back into the red at 16.4 + volts.
giammarco is online now
Last edited by giammarco; Sep 8, 2022 at 10:44 PM. Reason: new info
