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Old 03-21-2003, 12:38 PM   #1
bigvinnie
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headlights/dash lights pulsing at idle

What's the most common reason for this to occur...??? I suspect it's the alternator, but would like some opinions and experiences...

thanks.
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Old 03-21-2003, 01:10 PM   #2
JimKshortstep4x4
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From what you are describing it is the regulator, (either internal or external).

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Old 03-21-2003, 01:42 PM   #3
barn9
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My guesss would also be the regulator. Are you still using the old voltage reg? Internally regulated alternator will more than likely end this problem. It's a pretty easy changeover.
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Old 03-21-2003, 02:10 PM   #4
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well here's my situation......sometimes at idle when everything is on(lights, heater radio) if i give it a little more gas to bring the revs upto around 900-1000, the lights(dash and headlights) get brighter and the heater fan speed increases??? do i have the same problem, or is it the actual alternator??

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Old 03-21-2003, 02:12 PM   #5
bigvinnie
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barn9, yeah I still have the old style external regulator, might be a good time to change over....

I'll do a search cuz I know that subject has been beat to death... I would think this would be a good subject for the FAQ section...
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Old 03-21-2003, 02:16 PM   #6
Jason71k10
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sorry to weasel in on your post bigvinnie.....just reading it made me think of mine, so I asked a question,too

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Old 03-21-2003, 02:41 PM   #7
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Same thing was happening to me about a month ago, really bad. When I was at a stop sign at night I couldn't even see my guages. I actually ended up burning out one of my headlights. So, I replace my alternator and no more problem.
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Old 03-21-2003, 03:09 PM   #8
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Ensuring the alt is grounded properly sometimes helps this, but normally it is just the alt getting old.
Sometimes it just can't be avoided, and if it is only a little bit, I would ignore it personally.
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Old 03-21-2003, 04:08 PM   #9
bigvinnie
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looks like 3 votes for the external regulator and 2 for the alternator... switching to an internal regulated alternator should cover me in both cases...
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Old 03-21-2003, 07:27 PM   #10
lukecp
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I had a similiar problem, ignored it, and 6 months later my ext. voltage regulator went out. I replaced it at a whopping cost of $11, and it solved the problem. It wouldn't be a bad idea to upgrade to a internal regulated alternator though, i wish i would have done it when i replaced my alternator.
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Old 03-22-2003, 08:25 AM   #11
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My vote is that it could be either the regulator or the alternator. If the regulator is old, I'd just replace it and see if this fixes it. Even if it doesn't, you'll probably save some trouble down the road by putting a new one on.

Come to think of it, I've been putting off doing this on one of my Chevelles with the same problem...
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Old 03-22-2003, 09:10 AM   #12
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1/2 waving

One diode in the voltage regulator is open. That causes a pulsed dc output known as half-waving. Replace regualtor or entire alternator.......Zoomy
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Old 03-22-2003, 09:25 AM   #13
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Time to convert to a internally regulated alt.
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