I have a '99 with a suspected bad alternator.... Although it tested good at Advance Auto Parts, I am having charging issues... I have posted it all on here, and the general concensus has been to swap my alternator. The "diode bridge" may be bad (or something), or perhaps the brushes aren't touching when it's hot, etc.. So it wouldn't show up on a tester.. I don't completely understand all that, but that's what I have been told here.

A new alternator is between $150 to $200, which I do NOT have... I found a place that is parting out one, and they have the alternator for $50... Which I don't have either, but I can manage that. My question is this. They show two different alternators for it. One is 117 amps, the other is 136. Mine has power EVERYTHING, so I would assume mine has the 136 amp (though I could be wrong, just guessing)... The one that is being parted out has power door locks only, so I would assume it would have the 117 amp (again, just an assumption)... Is there any problem interchanging the alternator?? If in fact mine is 136, and the other one is in fact 117, is there any problem using it??? I do not have any big stereo system, or off road lights or anything. Supposedly there is no way to physically tell the difference.. Or even if I could tell physically, will using a lower amp alternator give me problems?


Thanks

 

If the same price, it's a safe bet to go ahead and get the 136 amp. I would compare product numbers just to see what yours came with stock because they have different numbers. Other than that extra amperage helps sometimes, especially if you might be adding a few accessories in the future, and have power everything.

 

I agree, but what I am saying is that I suspect the one on my Durango is the higher amp one.... My question is what if the one being parted out is the lower one?? Would that give me a problem??? Also, is there anyway to tell by looking at them how many amps they are? I looked at my old one and didnt see it marked anywhere.

 

Most likely not. If your truck is stock and you don't have a lot of high powered electronic/stereo gear running, then the biggest thing is it will just recharge your battery a little slower. As long as your normal driving habits are trips of at least a couple miles, it probably wouldn't even be anything you noticed.

When I was young and dumb, fresh out of high school with my first "real" paychecks and no responsibilities, I had about 7 grand worth of stereo equipment in my thousand dollar car (yes, I'm now old enough to realize how ridiculous that was. Sure was fun, though. ). When the bass drum kicked in my headlights would dim down to nearly nothing. I was very obviously running more than my alternator could handle. Even still, the battery stayed charged and I never had trouble starting the car.

If you're getting it at a good price, I'd probably go for it. I can't *promise* that you won't have issues, but if you're just running stock electronics, I'd be willing to bet 5 bucks that you'd be just fine.

 

so, I picked up the used alternator from the yard.... Installed it, BINGO.... My voltmeter on the dash is at high noon (14 volts). Although I now know for a fact my old alernator was 136 amp, because I ran the number online.. And the new one is the lower one, but it will do for now, and seems to be charging fine.

Sorry for all the icons, just wanted you guys to see what the party in my head looks like after "hopefully" solving the problem..

 

Alternators are nearly always one of the first cost cutting opportunities taken but paradoxically they are always sized for worst case. So if you manage to avoid idling in 100* heat while running all for power windows, moving your power seat, blasting the AC and stereo and rapidly cycling your ignition you probably will never notice. :-)

Realistically speaking your old alternator was probably pushing was less than rated output for a long time. If your volt is back up then you are probably golden but I would make sure to check the resistance on the main line from the alternator to the battery and give a once over of the PDC. Make sure there isn't any serious corrosion anywhere.

 

Sounds good Bike!