alternator intermittent failure
Thread Starter
6th Gear
Joined: Apr 2022
Posts: 6
Likes: 0
alternator intermittent failure
hello
i have a 86 conv. that seems to be having a possible Alternator problem. when i start the car the voltage goes up to around 18v with the red light on the dash , it slowly comes down and jumps back often
then often it acts normal about 14v
i have a new battery installed and still the same happens
ive checked the grounds and the positive connections to the battery and alternator and they all seem tight and good connections
any suggestions
ty
At6vette
i have a 86 conv. that seems to be having a possible Alternator problem. when i start the car the voltage goes up to around 18v with the red light on the dash , it slowly comes down and jumps back often
then often it acts normal about 14v
i have a new battery installed and still the same happens
ive checked the grounds and the positive connections to the battery and alternator and they all seem tight and good connections
any suggestions
ty
At6vette
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Instructor
Joined: Jul 2020
Posts: 226
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From: New Jersey
hello
i have a 86 conv. that seems to be having a possible Alternator problem. when i start the car the voltage goes up to around 18v with the red light on the dash , it slowly comes down and jumps back often
then often it acts normal about 14v
i have a new battery installed and still the same happens
ive checked the grounds and the positive connections to the battery and alternator and they all seem tight and good connections
any suggestions
ty
At6vette
i have a 86 conv. that seems to be having a possible Alternator problem. when i start the car the voltage goes up to around 18v with the red light on the dash , it slowly comes down and jumps back often
then often it acts normal about 14v
i have a new battery installed and still the same happens
ive checked the grounds and the positive connections to the battery and alternator and they all seem tight and good connections
any suggestions
ty
At6vette
As others have said, you can take it to a big-box auto parts place and they'll test it for you. Some places will just test it in the car by looking at the waveform while it's running. It sounds to me like the voltage regulator / diodes in the unit are failing. You should get it rectified quickly (that's a pun for the electrical engineers on here) or it will likely take out your battery or some other electronics that aren't tolerant of overvoltage.
Burning Brakes
Joined: Jun 2015
Posts: 1,183
Likes: 305
From: Shelbyville Kentucky
Not a Vette but had an alt that acted intermittent. Would actually passed the test at Autozone. Took it apart and could clearly see one of the brushes was barely making contact with the rotor.
Replace Alt.
Replace Alt.
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Melting Slicks
Joined: Jul 2005
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As other posters have said
1. Verify Clean and Tight Connections (both Pos & Gnd) at Alternator, Battery and at Starter Pos Terminal.
2. Verify voltage reading that you are seeing with a hand held VOM/Voltmeter (I'd check voltage at both battery and Alternator output post).
3. If voltage readings you're seeing are accurate - either have alternator tested, or simply replace it - odds are high that internal regulator is toast.
1. Verify Clean and Tight Connections (both Pos & Gnd) at Alternator, Battery and at Starter Pos Terminal.
2. Verify voltage reading that you are seeing with a hand held VOM/Voltmeter (I'd check voltage at both battery and Alternator output post).
3. If voltage readings you're seeing are accurate - either have alternator tested, or simply replace it - odds are high that internal regulator is toast.
Thread Starter
6th Gear
Joined: Apr 2022
Posts: 6
Likes: 0
Have you measured the actual battery voltage with a meter just to make sure it's not an issue with the dash/gauge cluster?
As others have said, you can take it to a big-box auto parts place and they'll test it for you. Some places will just test it in the car by looking at the waveform while it's running. It sounds to me like the voltage regulator / diodes in the unit are failing. You should get it rectified quickly (that's a pun for the electrical engineers on here) or it will likely take out your battery or some other electronics that aren't tolerant of overvoltage.
As others have said, you can take it to a big-box auto parts place and they'll test it for you. Some places will just test it in the car by looking at the waveform while it's running. It sounds to me like the voltage regulator / diodes in the unit are failing. You should get it rectified quickly (that's a pun for the electrical engineers on here) or it will likely take out your battery or some other electronics that aren't tolerant of overvoltage.
ill check and clean the connections when remove the cluster
ty for your input
Instructor
Joined: Jul 2020
Posts: 226
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From: New Jersey