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Discussion Starter #1
backing out of my driveway this morning i started smelling a burning smell and smoke coming out of my vents, popped the hood and smoke was billowing out of the alternator and flames shooting out of the back part of it!, now my question is that i know i need a new alternator, but is there something that causes this or just a failure internal to the alternator?
Need opinions ASAP, leaving friday for a long trip and dont wanna buy another alternator or burn my truck to the ground
thanks in advance
 

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Mr. Vehicle Destroyer
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sounds like your voltage regulator arced on something and caused it to catch fire. on second gen's the voltage regulator I believe is what controls charging, if that messes up it can cause an overcharge condition which will start to melt things.
 

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Things that cause early alternator failures are if you use an unregulated charger and damage the diodes. If you like to sit in the vehicle with the sterio on truck off, and when you start the truck, the alternator has to work hard to charge the battery, it overheats, and fails. If you have an oil leak that mists in the engine bay, mixed with dirt, then you will have a problem. Or it could have, just come apart internally and failed. Just a thought
 

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Discussion Starter #4
sounds like your voltage regulator arced on something and caused it to catch fire. on second gen's the voltage regulator I believe is what controls charging, if that messes up it can cause an overcharge condition which will start to melt things.
thats what i thought originally, but the flames werent from anything burning on the outside, it was coming from down inside the alternator, and as soon as i shut the truck off the flames stopped, nothing else in melted or burned, just the inside of the alternator
 

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Mr. Vehicle Destroyer
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they put a coating on the windings in the alternator, if the windings over heat that coating can burn off and short out coils which will make a really awful smell and a pretty nice light show....
 

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The voltage regulator on a '97 is in the PCM. Replace the alt and check voltage output at the battery terminals. If it is high (or low) you will need to do some more troubleshooting.
 

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Discussion Starter #7
ok guys, got it, must have been something internal, replaced it, charging normally
gone on a few drives without issue, thanks for the input!
 
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