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Alternator Swap Problem


DarkDragon
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SATURDAY:

Hey guys, I just did this swap yesterday. In the morning, my old alternator was running 14.3v and when I gave it load by turning on the head lights on high and the ac on full blast the voltage to drop to 13.3 and the car would stall out. In the afternoon I did the swap with a 94 Max alt. It worked great for about 5 minutes. I started the car and my multi-meter read 19v.wow what a jump. I gave it the load test again, dropped to 18v. Got below and tighten up a few thing, when I look back at my meter is reading 12.3v and dropping. Did I just blow my new alternator, fuse, or the flux capacitor? I can’t figure out what went wrong. Please help; I need this vehicle for tomorrow work.

 

Thanks

-------------------------------

 

SUNDAY:

Checked all wirings as the FSM. Everything seems to be fine and as you may know, the alternator turned out bad. Got it tested at Advance.

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MONDAY:

I got another new alternator from Napa. Swapped the pullies there. Came back home and installed the alternator. After installation, I plugged all the wires to the alternator. Then I connected the battery. Start the truck and these are my results.

 

alt2.jpg

alt1.jpg

alt3.jpg

 

What did I do wrong, and how can I fix this problem?

 

Thanks,

Tony

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I seem to remember someone (Simon?) saying the maxima alt wouldn't start charging until you get up to like 2000 rpm, maybe soemone else will chime in here that knows more about this. I do know 19 volts is NOT right, that is not good.

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the maxima one should work fine its a very common swap for the z31 I would check your ground and also get the alt tested again. have them test the new one at the store also. I have one on both of my z31's and they get 14.5v constant at idle and we both have a vg33 or vg30 in them and it works on both so theres no reason it shouldnt be working in the pathfinder too.

Edited by edicer2
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Is the voltage slowly rising?

 

Anyway, if you were reading 19V at your battery before with the old alternator, then that is bad... maybe something got busted? Of course, I guess you are asking what that could be...

 

with the new alternator from today, its dropping slowly. that's the voltage that you see. the higher i rev, the lower the voltage gets.

the 19v was from the 1st 5 minutes of the 1st alternator that was used for the swap. the old path alt was 14.2v when on and when load came on the volts dropped to stall out.

 

so yes, why am i the only one that i know that is not successful at this swap. i am thinking that i blew the circuit breaker from the FSM manual. but cant seem to locate it. the relay tested fine, along with the wiring.

Edited by DarkDragon
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At 19 volts you possibly blew a fuse link, that voltage is way to high

 

they should be near the pos wires right? anyways, i get the same voltage all the way to the alternator itself when i trace the alt wires.

Edited by DarkDragon
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You got a bad alternator, my first Maxima alternator did the same thing. It also wouldn't turn on unless I revved it to 3500RPM. New alternator in, no problems with voltage spikes, not charging sometimes, and not turning on.

 

I, being stupid, ran my Pathfinder at 18V for a few months. No damage done but the super bright headlights and gauges were nice.

Edited by Kingman
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You got a bad alternator, my first Maxima alternator did the same thing. It also wouldn't turn on unless I revved it to 3500RPM. New alternator in, no problems with voltage spikes, not charging sometimes, and not turning on.

 

I, being stupid, ran my Pathfinder at 18V for a few months. No damage done but the super bright headlights and gauges were nice.

 

 

funny... i think this is what i needed to kick thins thing in the ass to start charging. anyways, was getting mad seeing my voltage drop to about 10v. so i disconnect the multi-meter from the battery and connected it at the alt white cable and ground at the throttle body. voltage was the same at 10v. i got mad enough that i started revving it to 5k+ rpms. quickly the voltage jumped to 15v. brought the rpms back to idle and voltage stayed. i turned everything that i could think of on and the voltage dropped to 14.3v shut everything off and voltage raised back up to 15.15v

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ok, just got back from a test drive to the gas station. ran like poopy-cacas.

 

got some fuel thinking it was too low. while fueling up, i plugged in my multi-meter to the battery again. did the same crap at 11.9v at idle w/o load. revved it to about 5k and volts jumped to 14.8v w/o load and 13.6v with the lights and blower motor on. tried to take off on the gas station and the car wanted crap out like if it was misfiring. when it came up to temp, the path almost drove flawless.

 

WTF!!!!

 

please help.

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They are internally regulated, sounds like that's bad. Get another alternator lol.

Check!

 

You got a bad alternator, my first Maxima alternator did the same thing. It also wouldn't turn on unless I revved it to 3500RPM. New alternator in, no problems with voltage spikes, not charging sometimes, and not turning on.

 

I, being stupid, ran my Pathfinder at 18V for a few months. No damage done but the super bright headlights and gauges were nice.

Not a big deal to run overvolted as long as you don't pop all the lights on the dashboard. :lol: The ECU should internally regulate its own voltage too so it won't get hurt.

 

At 19 volts you possibly blew a fuse link, that voltage is way to high

You are less likely to melt any wires with higher voltage. I doubt the fusible link blew up.

 

ok, just got back from a test drive to the gas station. ran like poopy-cacas.

 

got some fuel thinking it was too low. while fueling up, i plugged in my multi-meter to the battery again. did the same crap at 11.9v at idle w/o load. revved it to about 5k and volts jumped to 14.8v w/o load and 13.6v with the lights and blower motor on. tried to take off on the gas station and the car wanted crap out like if it was misfiring. when it came up to temp, the path almost drove flawless.

 

WTF!!!!

 

please help.

Drops in voltage will screw with the sensors, especially the MAF sensor.

Edited by Tungsten
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They are internally regulated, sounds like that's bad. Get another alternator lol.

 

this was the second one. i had to use the warentee to cover the 2nd alt. if i were to get another, i would have to buy another. i have no more cash.

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You only get one shot at warranty? Isn't that like illegal or something?

 

not really. if i had 5 pathy, than how would you explain 5 alternators and 5 fuel pump claims(exaggeration). they did not function correctly?

 

in my case, true on a crappy alt. they giving me 90 days before i come back with this issue.

 

as of right now. same crap, the path stalled everywhere and stumbling like running on 3 cylinders.

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not really. if i had 5 pathy, than how would you explain 5 alternators and 5 fuel pump claims(exaggeration). they did not function correctly?

 

in my case, true on a crappy alt. they giving me 90 days before i come back with this issue.

 

as of right now. same crap, the path stalled everywhere and stumbling like running on 3 cylinders.

No. fskc that. Go back there and tell them to shove it up their asses. It's the same part, brand &^%*ing few. You JUST pulled it out of the box 2hours ago. They can't do that. I thought NAPA was a premium store with more knowledgable employees than some stupid teenagers telling you a Chevy LUV doesn't exist. I guess I was dead wrong.

 

All stores run that risk of "5 Pathfinders with 5 broken alternators" or whatever. Napa ain't anything special.

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as of right now. same crap, the path stalled everywhere and stumbling like running on 3 cylinders.

Did this happen right after you replaced the alternator? I ran my truck with the alternator disconnected before and it didn't do that. All it did was run with the Battery and A/T Oil Temp light on.

Edited by Tungsten
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It seems alternators are very prone to failure. Especially replacements. The stock ones are good. My dad is on his 4th, FOURTH (meaning this is his 5th total alternator), warranty replacement in 2years. Don't get alternators from Pep boys. Now he's stuck. They won't let him get a refund, they just keep giving him new ones. You might not want to get another warranty replacement. Just return it and get a Nissan one from the dealer. I guess it would actually be a Hitachi one?

 

After rereading your posts, it seems like you might have problems that are unrelated to the alternator in addition to the alternator. You might have knocked some sensors loose of some wires if it's running that rough

Edited by 1994SEV6
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not really. if i had 5 pathy, than how would you explain 5 alternators and 5 fuel pump claims(exaggeration). they did not function correctly?

 

in my case, true on a crappy alt. they giving me 90 days before i come back with this issue.

 

as of right now. same crap, the path stalled everywhere and stumbling like running on 3 cylinders.

 

There's a difference from returning a clean "new" alternator and returning 5 busted old dirty ones.

 

This is all making me think I should buy one of those ludicrous expensive green alternators from rugged rocks.

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There's a difference from returning a clean "new" alternator and returning 5 busted old dirty ones.

 

This is all making me think I should buy one of those ludicrous expensive green alternators from rugged rocks.

 

They are nice but you will have to upgrade your charging harness.

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Nope, changing that harness is easy as pie. That is more money you have to spend though.

I tried to get a REMY gold but they went on back order. :( So I ended up with a real Nissan Maxima one I took to a rebuilder and got it back like new. :)

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