Pulsing electrical current

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jeff22374
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Pulsing electrical current

Post by jeff22374 » Fri Mar 17, 2017 10:07 am

Hi. First post here and hopefully I can get some info/answers. My '05 FS SEL original alternator housing cracked at about 162,000 miles. I replaced with a reman from local Ford Dealership. Upon install, noticed that ALL lights (interior, dash & exterior) were pulsing intermittently with no regard to engine RPM and fan speed as well as idle RPM were slightly faster/higher and then would drop, indicating voltage output discrepancies. Changed out 2nd alternator with another from same shop and problem still exists. Car seems to be running fine sans these few issues and I really do not want to try and replace the alternator again (who would put it on the bottom of the engine behind the wheel is an idiot!). Any thoughts/suggestions would be most appreciated!

pmassey31545
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Re: Pulsing electrical current

Post by pmassey31545 » Fri Mar 17, 2017 6:49 pm

Not sure where the voltage regulator is, but a lot or most newer cars have them built into the alternator. What are the chances you'd get 2 bad Alts? Not probable...but possible. Either that or you have a loose wire or bad connection.
2007 Limited AWD
2002 F150 Lariat Supercrew, 2005 Kawasaki 1500 Classic, 1999 Toyota Camry, 2010 VW Routan

pmassey31545
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Re: Pulsing electrical current

Post by pmassey31545 » Fri Mar 17, 2017 6:56 pm

What about this? Put it in test mode and see if the voltage fluctuates. If so, you know it's probably the charging system.

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2007 Limited AWD
2002 F150 Lariat Supercrew, 2005 Kawasaki 1500 Classic, 1999 Toyota Camry, 2010 VW Routan

RVAFreestyle
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Re: Pulsing electrical current

Post by RVAFreestyle » Fri Mar 17, 2017 9:55 pm

Double check all your connections on the alt, battery and check your cables. Two failures os highly unlikley particularly with genuine FoMoCo replacment parts.
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jeff22374
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Re: Pulsing electrical current

Post by jeff22374 » Sun Mar 19, 2017 10:16 am

Pmassey...thanks for the suggestions. Voltage regulator is internal. After I replaced alt. a second time, I took over to the dealer (I know a guy who works there) and he put it on the computer...everything checked out. Now, it was a very basic test, but no voltage fluctuations were showing.

jeff22374
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Re: Pulsing electrical current

Post by jeff22374 » Sun Mar 19, 2017 10:16 am

All connections are tight...first thing I checked, but thank you for the suggestion!

pmassey31545
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Re: Pulsing electrical current

Post by pmassey31545 » Sun Mar 19, 2017 11:04 am

I'm not picking on the shop...but maybe they don't know how to check or fix alternators as good as they think they do.

I know it's money and everyone likes to keep theirs...but take your alternator to a parts store. Autozone is real good I think. Have them test it...on their machine. Then if it shows bad, buy one from them. If it's not the problem, they will let you return it. You can't lose.

Just seems too odd that you had alt problems...replaced your alt...it was bad...replaced again (from same shop) and still have alt problems.
Last edited by pmassey31545 on Mon Mar 20, 2017 7:17 am, edited 1 time in total.
2007 Limited AWD
2002 F150 Lariat Supercrew, 2005 Kawasaki 1500 Classic, 1999 Toyota Camry, 2010 VW Routan

jeff22374
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Re: Pulsing electrical current

Post by jeff22374 » Mon Mar 20, 2017 6:32 am

I'm actually wondering if the original alternator, when it went bad, surged and did something to the computer component that monitors voltage.

pmassey31545
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Re: Pulsing electrical current

Post by pmassey31545 » Mon Mar 20, 2017 7:17 am

jeff22374 wrote:I'm actually wondering if the original alternator, when it went bad, surged and did something to the computer component that monitors voltage.
Possible. But again, I would guess the probability is low...but possible.
I know it's money and everyone likes to keep theirs...but take your alternator to a parts store. Autozone is real good I think. Have them test it...on their machine. Then if it shows bad, buy one from them. If it's not the problem, they will let you return it. You can't lose.
^^^^^^^^^^
This. Do this. Just to make sure.
2007 Limited AWD
2002 F150 Lariat Supercrew, 2005 Kawasaki 1500 Classic, 1999 Toyota Camry, 2010 VW Routan

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