Voltage fluctuation-alternator going?
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Joined: Dec 2001
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From: Anch., Alaska
Voltage fluctuation-alternator going? starting tonight, I noticed at warmup, my dome light, and headlights started barely dimming and brightening quickly at idle. Not alot, but noticeable. I looked at my volts gauge, and it was fluctuating, too. Normally above 14, around 15, it would dip to 13 and quickly rise again, over and over, kinda quickly. It stopped, then started again, even while driving. Started it again cold, it didn't do it, then did it again after warmed up. I looked at my battery cables and alternator cable, and they were tight.
Is my alternator going or something? It has about 23,500 miles on it. I have a couple amps for the stereo(been in for a couple years), but never a problem like this before today.
Battery always charges ok. I know some of you guys have had failed alternators. Did it do this? I wouldn't think it would fail with the low miles, but who knows, having my amps, and also a supercharger pulling on the pulleys all the time :\ Any ideas? Thanks for any help. Sam
2000 Chevrolet Silverado ext cab LS
Is my alternator going or something? It has about 23,500 miles on it. I have a couple amps for the stereo(been in for a couple years), but never a problem like this before today.
Battery always charges ok. I know some of you guys have had failed alternators. Did it do this? I wouldn't think it would fail with the low miles, but who knows, having my amps, and also a supercharger pulling on the pulleys all the time :\ Any ideas? Thanks for any help. Sam
2000 Chevrolet Silverado ext cab LS
it could be either one, but you should go with a bigger battery or one made for hanldling the stereo. like a yellow top optima batter. i think that is the one. it is worth the price. good luck with finding the problem
You should check the voltage /amperage w/proper test equipment.
The instrument cluster gauges are not exactly precision swiss instruments.
But the lights constantly pulsing is a sign of possible alternator problems.
The instrument cluster gauges are not exactly precision swiss instruments.
But the lights constantly pulsing is a sign of possible alternator problems.
Thread Starter
TECH Apprentice
Joined: Dec 2001
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From: Anch., Alaska
I would love to test it, but it only does it sometimes.
Is it possible that the alternator is going bad if it only does it, on and off?
It has to either be the Alt. or the cable coming off of it.
Is it possible that the alternator is going bad if it only does it, on and off?
It has to either be the Alt. or the cable coming off of it.
Originally Posted by Procharged LM7
Is it possible that the alternator is going bad if it only does it, on and off?
There are tests that can be done still , like checking the ripple pattern of your alternator, it will show up , if it is current or not.
Thread Starter
TECH Apprentice
Joined: Dec 2001
Posts: 357
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From: Anch., Alaska
Originally Posted by wrencher
Yes it is possible the alternator is intermittantly faltering.
There are tests that can be done still , like checking the ripple pattern of your alternator, it will show up , if it is current or not.
There are tests that can be done still , like checking the ripple pattern of your alternator, it will show up , if it is current or not.
Well, what a day. I went to Napa to get my alternator tested, and it tested ok, but it doesn't suprise me, cause it was doing the fluctuating sporadically, and I could hear the bearings just starting to squeak a little, so I got a new one. I has a gold pulley on it compared to the stock black pulley. I decided to put a new belt on at the same time, as my first one is barely worn, just to be safe.
Those of you who have changed your belt with a Procharger know what is involved in this. Got the new one on, and won't go on, too short, even though the same size as the one I just had on. Tried many things, wouldn't go. I took it off, put the old one back on, WON"T FRICKING FIT! The gold pulley(on the new alt.) must be a little bigger or something.
Napa said they would swap pullies for me, so I get my old Ford fired up to drive there(never drive it, no turn signals, and is old) the bitch starts overheating, so I have to come home, without going to Napa to get the pullies swapped.
Why would they have a different pulley on the alternator. The new alt. is the same 105 amp as stock. I didn't get the bigger 140 amp one, because the belt might not fit :\
All this, and it may not even solve my problem when I am done.Not to mention the 25 degrees and rain/snow to work in for 5 or so hours. Dammit.
Will the cold make the belt shrink that much to where I can't get it on maybe?
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Thread Starter
TECH Apprentice
Joined: Dec 2001
Posts: 357
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From: Anch., Alaska
nah, it's the right size. The cold makes the belt shrink like an inch(belt is a 1115, so an inch is less than 1%) so it wouldn't go on. I finally got it. Used a heat gun, and an elec space heater and some alignment punches to get the top idler pulley back in. That seemed to be the easiest way, taking out the top pulley, then pushing the belt back down, and putting the pulley back in. Still a major bitch! It was about 25 when I was working on it.
Haven't had it flutuate again, yet, so we'll see.
There are three of us Procharger owners that have the same problem, and one of them said maybe the aux fuel pump is pulling a bunch of current once ina while for some reason. Who knows. Just glad to have it running again for now. Thanks for the help Wrencher
Haven't had it flutuate again, yet, so we'll see.
There are three of us Procharger owners that have the same problem, and one of them said maybe the aux fuel pump is pulling a bunch of current once ina while for some reason. Who knows. Just glad to have it running again for now. Thanks for the help Wrencher
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