alternator issue

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Jan 22, 2008 | 07:16 PM

metal13x

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alternator issue

hey guys, i have a simple question. I just put a new alternator in my 97 F-150 (4.2L). Everything seems to be running fine however, I noticed last night that when I turned on my dome light, the light was kind of flickering. It only happens when the engine is idling and the electrical system is under load (headlights, heater and radio is on). When I rev the engine, the light stays normal, then when it comes back down to idle, it flickers again. I know its not my battery, because its only a month old. This did not happen with the old alternator. Could this be a connection issue, or is my alternator defective?

Jan 22, 2008 | 08:22 PM

steve(ill)

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you might check the plug to make sure it seated good, and no corrosion. make sure the ground strap from motor to frame is clean and not corroded. other than that, i would guess the voltage regulator is slightly off and not keeping up at low RPM. not much you can do with that. live with it, or change out again-- maybe tell the guy you bought if from and see if he will trade it out.

Jan 23, 2008 | 07:03 AM

Spotty

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From: Minnesota

I have had similar problems after replacing altenators. I went thru 3 on my truck before I got one that didn't have excessive whine under load, or the dreaded slight flicker of the lights at idle. I only buy name brand stuff now and have had better luck.

Spotty

Jan 23, 2008 | 08:52 AM

metal13x

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well, i bought the alternator at napa, and its got a lifetime warranty. maybe ill live with it for now and exchange it later. hopefully they will exchange it if i explain the flicker issue. a warranty is a warranty, right?

Jan 23, 2008 | 12:50 PM

Spotty

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From: Minnesota

Mine all came from NAPA also, I just wasn't happy. Number 3 is a Delco, also from NAPA, that they gave me at the same cost as the previous 2 I brought back. I had 3 alternators in 1 week from NAPA till they finally gave me the Delco to try. This one is quiet, no whine or flicker. Even my buddy at NAPA says the quality of their own line is not consistent. The sooner you take it back, the better for all. It may have a lifetime warranty, but I would address the issue now. Let us know how you come out..

Spotty

Jan 23, 2008 | 02:36 PM

charlesh

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From: Maryland

Had issues with rebuilt alternators for other vehicles. They seem to be hit and miss...

I had someone else do the work so they were out the hours when the first rebuilt had to be replaced. But getting stranded and out the vehicle for a day etc. is no fun...

I don't know how to resolve this since the price difference on rebuilt versus new is often great...

Jan 27, 2008 | 11:40 PM

metal13x

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Fixed!

well, i took the 15 minutes to take my new defective alternator out and exchanged it at napa for a different one. This one doesn't flicker, whoohoo, problem solved, easy fix. Well, thanks to all for the input.