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My ass, your face
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Discussion Starter · #1 ·
heres the story:

im driving along and i notice my battery and brake lights coming on and off on my dash...knowing these are signs for an alternator, i replace it asap with a brand new one. i get the new one installed and it only puts out 11v. wtf. i then install my old one and it reads the proper voltage. great. i then get a known to be good alternator from a friend and i install it, to which it reads 14v. awesome...the battery is good and "new". i replaced the battery terminals with brand new ones...but i end up replacing the negative terminal cable with a new 2gauge cable. now, the car runs fine and everything charges like it should..only problem is that when i use something that takes electricity, the voltage drops. for example, if im driving and stop, the volts go down by 1-2v(autometer voltmeter)....turn on the headlights..volts drop a bit, then climb back up. play a song with bass(system) and the volts drop. i get out of the car and use a voltmeter while the car is on and test the alternator..it reads 14v, i then have my bro turn the headlights on..as soon as the lights come on, the alternator pushes out 14v for a second and then suddenly drops to 13v then immediatly climb back up to 14v. what do you guys think the problem could be? i know i have good battery connections, the negative battery terminal is double grounded as well.. im stumped? not to mention that the battery and brake lights still flash intermittely here and there(no matter what alternator i use)
 

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My ass, your face
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Discussion Starter · #3 ·
im having a brain fart or something...but what do you mean by IP?
 

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Even with a brand new alternator and battery I still feel some power loss whenever I turn something on (radio, lights, heat/air, etc). I hear the best way to fix the problem is an UR pulley. Not sure what your exact problem might be AJ, i'd recheck all the connections again.
 

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My ass, your face
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Discussion Starter · #5 ·
irontom said:
Even with a brand new alternator and battery I still feel some power loss whenever I turn something on (radio, lights, heat/air, etc). I hear the best way to fix the problem is an UR pulley. Not sure what your exact problem might be AJ, i'd recheck all the connections again.

yea no kidding...im having severe power loss with this alternator. i have the UR pulley. this is the thing though..the alternator SHOULD always put out 14v no matter what...so when i turn something on in my car such as the headlights..why would my alternator stop pushing volts for a second then jump back up? that just doesnt make n e sense to me.
 

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My ass, your face
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Discussion Starter · #7 ·
Nostrodomas said:
What kind of condition is your ground wire in?

BRAND NEW freshly installed 2gauge. im starting to wonder if the 2 gauge has anything to do with it. seing as how the stock ground is like 4gauge. the stock ground has 2 grounding points(chassis and trans). the parts store grounds only have one point(transmission) so i added another ground from the terminal to the chassis and it still acts up.
 

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Proud 2004 X-Trail Owner
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All cars do the same thing, specially at Idle Speed, turn A/C while lights were turned on & you'll see the volts dropping a lot.

At FSM you could see that:

GA16 alty gives [email protected],300RPM's
SR20 alty gives [email protected],300RPM's

Idle speed is much lower, sometimes not enough to withstand a higher energy demand.

I suggest you to look for a cigarrete plug with wires, connect the voltmeter & go with a passenger for a ride, (looking the voltmeter & telling you changes) do the same turning lights, A/C, sound, etc. while accelerating that volt losses has to be much lower than at idle.
 

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My ass, your face
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Discussion Starter · #9 ·
manuelga said:
All cars do the same thing, specially at Idle Speed, turn A/C while lights were turned on & you'll see the volts dropping a lot.

At FSM you could see that:

GA16 alty gives [email protected],300RPM's
SR20 alty gives [email protected],300RPM's

Idle speed is much lower, sometimes not enough to withstand a higher energy demand.

I suggest you to look for a cigarrete plug with wires, connect the voltmeter & go with a passenger for a ride, (looking the voltmeter & telling you changes) do the same turning lights, A/C, sound, etc. while accelerating that volt losses has to be much lower than at idle.

well the funny thing is that it NEVER used to do this...i mean, i could SEE the needle on my autometer gauge move dramatically...before, i couldnt even notice a difference in volt changes. i think i might have a bad ground somewhere...dont know where though
 

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System? what kind, same thing happens in my car, I have a cap with a voltage meter on it for my system and I noticed the same fluctuations while driving. I'm guessing that its not abnormal if you have a greater power demand on your electrical system than stock. Its most likely your system thats causing the problem. Before I got my cap, my new system killed my alternator n my battery, for a while my car wasn't even running. At first my battery terminals were corroded so I thought it was that, got it replaced and cleaned, car drove fine for a while. Then one day tried to start it nothing, so I jumped it, started, so I figure battery. Nope, after about 5 minutes car dies, jump it again, rev the engine a lil bit, putter, weaken, dies. So i'm like ok lets call the tow truck, call it guy comes jumps it reads the voltage on the alternator, its fine, so then he says turn the defogger on, car dies. So he's like your getting a power draw from somewhere, "well duh". Take it too the shop they look at it can't figure it out," take the system out, and bam car works fine". So I got a cap for 200, problem solved.

So what i'm trying to say is disconnect the system and try reading the voltage, doing what manuelga suggested. See what it reads with the system disconnected if its better or the same. If its better w/o the system just get a cap, to take the stress off your alternator.
 

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My ass, your face
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Discussion Starter · #12 ·
the system's been in the car for a long long time now with no previous problems. however, i did have the thoughts earlier today to disconnect the system and see if anything is going down with it.
 

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My ass, your face
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Discussion Starter · #13 ·
belt tension?

something has occured which leads me to believe that the belt tension is restricting flow to the alternator. as we all know, the alternator creates power from the rotating forces created off the pulley which is driven by the belts. i have NO explanation as to why my volts would drop straight from the alternator when i have an increase in power demand(headlights/stereo etc.) so when a higher load is put on the alternator...it means the alternator must work a bit harder to push out more volts...so if the belt tension is too tight..its restricting the the alternators ability to make power..this is only an assumption. it also is kind of the only explanation as to the problems i am having. from what i can see driving at night or day time is that every here and there, there is power loss somewhere in the car causing my headlights to go dim every once and a while....causing my autometer volt gauge to drop to about 10v and interior lights going dim...however, it has NO adverse affect on my cars audio system including a 1200w amp and 2 subs. this is some crazy shiznit! im totally lost
 

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Proud 2004 X-Trail Owner
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You have a sleeper fail: something that appears suddently without any reason, 10V is too low.

Have you checked ALL fuses below the hood? Maybe some larger fuses blow when alty was changed & the circuit is taking energy from a different source, some change you made when system was installed or any other non clearly identified.

Or... maybe, just maybe terminal at your alty is not getting a good signal, look for EL-35 & 36 pages at FSM for better explanation of the system.
 

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My ass, your face
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Discussion Starter · #16 ·
manuelga said:
You have a sleeper fail: something that appears suddently without any reason, 10V is too low.

Have you checked ALL fuses below the hood? Maybe some larger fuses blow when alty was changed & the circuit is taking energy from a different source, some change you made when system was installed or any other non clearly identified.

Or... maybe, just maybe terminal at your alty is not getting a good signal, look for EL-35 & 36 pages at FSM for better explanation of the system.



yea, i had checked all fuses under the hood...not under the dash yet though. i was looking at the FSM earlier today on all the electrical stuff...however since its in PDF formatt, it is kind of hard to read
 

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Proud 2004 X-Trail Owner
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It's too easy, the connector (mine is gray) at your alty got 2 wires:

one is [L] it turns on dash light when they don't receive energy,
the other is , that's the return of energy to the alty.

That last one could have a intermitent false connection & making the whole mess
 

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My ass, your face
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Discussion Starter · #19 ·
manuelga said:
It's too easy, the connector (mine is gray) at your alty got 2 wires:

one is [L] it turns on dash light when they don't receive energy,
the other is , that's the return of energy to the alty.

That last one could have a intermitent false connection & making the whole mess



yea, there is a red/yellow wire and a yellow/gray wire... i mightve figured the problem lies therein...however, finding WHERE in the electrical wire mess is the problem is what proves to be difficult. finding where those wires lead isnt all that easy. haha, i know one of them leads to the dash(gauges) and the other one im pretty sure leads to the battery.
 

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cHoPs said:
yea, there is a red/yellow wire and a yellow/gray wire... i mightve figured the problem lies therein...however, finding WHERE in the electrical wire mess is the problem is what proves to be difficult. finding where those wires lead isnt all that easy. haha, i know one of them leads to the dash(gauges) and the other one im pretty sure leads to the battery.
At the FSM: Y/R is [L] & R/B is

But you can check at your alty (printed at the plate) wich one is that one could be the bad guy.
 
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