Author Topic: Alternator gets too hot to touch  (Read 2142 times)

Offline silverchev08@gmail.com

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Alternator gets too hot to touch
« on: February 23, 2019, 08:12:04 AM »
85 GMC K20 - new alternator - replaced what was installed.
Is it normal for an alternator to heat up to the point where I can't hold my hand on it? I mean the truck seems to be running fine for now. Can also heat bubbling in battery after driving truck for a while. Battery is new as well. Checked amperage at battery terminals while truck is running and display reads 14-15. Any thoughts?

Offline silverchev08@gmail.com

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Re: Alternator gets too hot to touch
« Reply #1 on: February 23, 2019, 01:20:02 PM »
Okay one more tidbit of information. While truck was running tested leads with my multi meter and voltage at battery while running is 16.74 . I guess this is obviously way too much and is the reason why the alternator is getting hot it's charging the battery overcapacity. Thoughts?

Offline Irish_Alley

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Re: Alternator gets too hot to touch
« Reply #2 on: February 23, 2019, 01:50:00 PM »
yeah i would say something isnt right with it. does always read 16+ volts? take it back to the parts store so they can bench test it
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Offline VileZambonie

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Re: Alternator gets too hot to touch
« Reply #3 on: February 23, 2019, 05:23:41 PM »
Replace the alternator
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Offline silverchev08@gmail.com

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Re: Alternator gets too hot to touch
« Reply #4 on: February 23, 2019, 06:59:42 PM »
Its brand new though

Online bd

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Re: Alternator gets too hot to touch
« Reply #5 on: February 23, 2019, 07:30:49 PM »
With the engine running, measure the voltage at the #2 regulator terminal (image) and compare that with the voltage measured at the alternator B+ output post and the battery positive post.  Use the same voltmeter ground connection for all three measurements.  Then measure the voltage drop between the battery negative post and the alternator case.  Post all results.


Rich
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Offline silverchev08@gmail.com

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Re: Alternator gets too hot to touch
« Reply #6 on: February 24, 2019, 12:37:35 PM »
Started the truck up this morning and battery was being charge to 19 V. Turned off the truck disconnected everything and took the alternator back to Napa and swapped it out. Just installed new alternator and voltage at battery while truck is running is 14.8. Think we're good to go. Anything else I should check?

Offline JohnnyPopper

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Re: Alternator gets too hot to touch
« Reply #7 on: February 25, 2019, 12:30:30 PM »
One last thing: Is there cold beer in the fridge?
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Offline philo_beddoe

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Re: Alternator gets too hot to touch
« Reply #8 on: February 26, 2019, 09:44:25 AM »
Just keep throwing parts at it until fixed. Theoretically, you'll eventually end up with a perfect new running vehicle. Good job...
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1