Alternator issues.Help needed!

dragonh

dragonh

Member
Car
2005 FX35 AWD
Hi all, 3 weeks ago, my oem alternator went..While testing, it read 12.2, then blew out a coil with a puff of black smoke..Changed the huge electric harness with the coil but OEM alternators here run 1,400 USD so my buddy got me a new aftermarket one for 150 USD..That lasted 2 days..stated up..Voltage was 13.8(normal) drove for about 45 mins,,parked in an outside carpark..Tried to start it again after I turned off the ignition as I had to back up a little more...Wouldnt start..All lights on the dashboard were flashing like crazy..Had to get it towed to the shop...Alternaror was not charging the battery..2nd replacement alternator was put it..They kept it at the shop for 4 days, checking voltage and,temp as well as mountain driving and road driving..All ok..So I thought! Drove yesterday..voltage was 13.7/8 but after driving for a couple of hours,and on the way home..Volyage dropped to 12.5 and water temp went up as well.
Seems that when I drive up a small mountain road or the car gets hot, voltage drops..All coolant in the tanks are normal! Wires were checked after the 2nd aftermarket alternator was put it..(No shorts)..As I am Stillen SC with more power, MUST/SHOULD I get an OEM alternator?
Any suggestions on what it could be or what else I can check..Thanks all
 
Can't see a reason a supercharged car had to go with oem alternator. Have the shop test the battery? How old is the battery? Your car gets hot and battery/alternator are separate problem to me. Coincidence to me.
 
la_fx35 said:
Can't see a reason a supercharged car had to go with oem alternator. Have the shop test the battery? How old is the battery? Your car gets hot and battery/alternator are separate problem to me. Coincidence to me.
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Battery is Amaron Pro..1 year old.
No prob with the battery! Yesterday while driving the voltage dropped from 13.7 to 12.6...thus going up a hill, water temp went up, due to my fans running at a,slower speed..
 
dragonh said:
Battery is Amaron Pro..1 year old.
No prob with the battery! Yesterday while driving the voltage dropped from 13.7 to 12.6...thus going up a hill, water temp went up, due to my fans running at a,slower speed..
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There must be something inside the OEM alternator that runs 1400 USD here compared to the 150 bucks aftermarket!
 
Check your fuses and wiring again. On a previous Nissan, I replaced the alternator with a larger aftermarket one for the stereo and it was shorting out under load. It installed fine but under throttle the engine would shift enough that the alternator body and a wire could contact the car's chassis and shorted out the main fuse. When the fuse blows the alternator stops charging and to conserve battery, the radiator fans stop working. My car would overheat when the fuse went. On some cars, the entire car will die but on Nissans it will limp for a while longer on battery alone.

Isn't the voltage regulator part of the alternator? That could be causing issues as well.
 
Bi
shadow191 said:
Check your fuses and wiring again. On a previous Nissan, I replaced the alternator with a larger aftermarket one for the stereo and it was shorting out under load. It installed fine but under throttle the engine would shift enough that the alternator body and a wire could contact the car's chassis and shorted out the main fuse. When the fuse blows the alternator stops charging and to conserve battery, the radiator fans stop working. My car would overheat when the fuse went. On some cars, the entire car will die but on Nissans it will limp for a while longer on battery alone.

Isn't the voltage regulator part of the alternator? That could be causing issues as well.
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Hi all, Got my prob sorted out..Put a used OEM alternator on first but prob was the grounding.
Re cleaned all grounding points but voltage was still showing 12.7 on both my voltage gauges...So my specialist added 5 more heavy duty grounding wires to the engine bay and Bingo, gauges read 13.8 when started up..Been driving every day in 40oc temps for 3 weeks now and so far so good...The alternator prob did drain the shit out of my newish Battery so had to throw in a Bosch platinum....So I would suggest anyone with a modded engine SHOULD add extra grounding...4 or so is enough..Voltage went from 12.7 to 13.8 with those grounding wires. Tks 4 all the replies and suggestions.
IS is the best!
 
So was the bad grounding preventing the battery from charging? The difference in voltage is exactly the difference you would see between alternator charging and not. Glad to hear you got it fixed.
 
shadow191 said:
So was the bad grounding preventing the battery from charging? The difference in voltage is exactly the difference you would see between alternator charging and not. Glad to hear you got it fixed.
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Yup! Bad grounding was preventing it. 6 extra grounding wires were also added..tks 4 ur help and concern bro!
 
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