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On my way home from town I set the cruise and the truck started bucking and jerking on cruise control. Cancel cruise control throttles fine, Set cruise again bucking and jerking. So I pull over unplug the field lead and drive home. No issues at all. Pull out my Fluke DVM and measure at the BATT terminal of the alternator and was getting 0.244 not a typo... So of to the part store again to get another alternator under warranty.

Edited by Mopar1973Man

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  • Mopar1973Man
    Mopar1973Man

    Updated video... Other videos are deleted now as well so this is the only video in my library for AC noise testing now!    

  • Mopar1973Man
    Mopar1973Man

    When I get some more free time I'll do just a "Alternator AC Noise" article.  

  • Mopar1973Man
    Mopar1973Man

    Unknown why but it failed the NAPA test stand. The new one pasted. So I can say that bad alternator diodes can do some really weird things like bucking and jerking with fly by wire cruise control.

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I thought AC noise came from high voltage transmission lines? 

 

Seriously, it's amazing how original equipment can last for decades and replacements aren't worth a hoot. We've become accustom to prices that originate in China and then when faced with real quality it's tough to chew. But if you factored in inflation, some of the "high end parts" are not so out of line. 

Try doing same test and rev engine up, AC noise on mine goes up doing it that way. Which I guess is normal.

On 6/8/2016 at 10:51 AM, Dieselfuture said:

Try doing same test and rev engine up, AC noise on mine goes up doing it that way. Which I guess is normal.

 

ive done that.  my mechman alternator is within our accepted standard spec at all rpms.  

7 hours ago, CSM said:

 

ive done that.  my mechman alternator is within our accepted standard spec at all rpms.  

My Mechman is going strong also

So just today I was driving in town and both me and my daughter thought we could smell a faint electrical burning smell I had the ac going. I'm not so sure it was coming from my truck. However my volts are lower than normal and I can hear a humming whining noise coming from the alternator that wasn't there before. So is the humming a sign of a bad alternator?

It could be, it would be easy enough to test.

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11 hours ago, lrhull said:

So just today I was driving in town and both me and my daughter thought we could smell a faint electrical burning smell I had the ac going. I'm not so sure it was coming from my truck. However my volts are lower than normal and I can hear a humming whining noise coming from the alternator that wasn't there before. So is the humming a sign of a bad alternator?

 

27 minutes ago, Hawkez said:

It could be, it would be easy enough to test.

 

Grab your DVM and start testing...

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On ‎6‎/‎6‎/‎2016 at 3:41 PM, Mopar1973Man said:

Just a screw driver... LarryB's diodes are expensive I can keep rolling alternators over on warranty for less. I'm thinking of getting of ahold of National Alternators and getting a high output diode pack and go from there.

Is it possible to mod an alternator so the diodes are external and you could change them out while the wife goes and buys you a Milkshake and  hamburger? Just a drweamer here but, one more way our trucks could have a more reliable set up.

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Once the alternator is removed which isn't hard. Just grab a phillips screwdriver and take a few screws out and replace. Changing diodes on the road side is nothing. Even changing the brush pack is easy too its only 3 screws. So that being said just need a source of quality diodes being that is about the only thing there is a problem with. Brushes are cheap at LarryB but the diodes are nearly the price of an re-man'ed alternator.

 

http://www.fostertruck.com/diode-pack-rectifier-bridge-for-dodge-denso-alternator.html

 

http://www.fostertruck.com/brushes-for-dodge-denso-alternator.html

Edited by Mopar1973Man

This is the rectifier and repair kit that I bought for my alternator rebuild.  It is much cheaper than Larry Bs.  I should have done a write up, but I never took any pictures.  I googled how to rebuild the Denso alternator and found a pretty decent video (probably shouldn't drop yours as he demonstrates in the video). The brushes and rectifier are very simple.  The bearings aren't hard, but they require the persuasion of a hammer.  After buying the kits and paying for shipping I rebuilt my alternator for almost the same price as a unit from OReilly...and I get to warranty it myself.  But it did solve my high AC problem. 

 

http://www.aspwholesale.com/rectifier-nd-p1375.html

http://www.aspwholesale.com/repair-kit-nd-er/if-136a-p6046.html

 

 

Edited by Hawkez

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I've heard a lot of bad things about rebuilds. Since they give a lifetime warrantee to meet competition they just provide another quick and fast rebuild when yours goes bad.

 

Example, my oem starter motor lasted years on my first gen truck but now that I'm on free rebuilds... third one now... they only last about 2-4 years now.