# 01 sentra electrical



## djames (Mar 10, 2008)

new to the form , but glad i found it. The question i have is does any1 else have problems with there electrical . my lights will dim if heat on of if the rear defrost is on . it also causes the rpms to increase. Anyone have any ideas, its not a big problem i have had the sentra for 3 years and no problems it has 120 thousand km on it.


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## saint0421 (Sep 24, 2006)

djames said:


> new to the form , but glad i found it. The question i have is does any1 else have problems with there electrical . my lights will dim if heat on of if the rear defrost is on . it also causes the rpms to increase. Anyone have any ideas, its not a big problem i have had the sentra for 3 years and no problems it has 120 thousand km on it.


I used to have those very same issues. I still do, just not to the extent as to where it's a concern or it's hardly noticable anymore since I've installed a light-weight crank pulley and optima red top battery. I think the Nissan OEM or equivalent batteries are crappy. When your heat/AC/rear defrost is turned on it causes an increase in electrical load on your car's charging system. Which in turn draws power from other sources. If you think it's a serious concern get your car's charging system checked out (battery & alternator).


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## djames (Mar 10, 2008)

thats a good idea. the funny thing is, i thought it would be more in depth but i will try upgrading the battery and alternator. Its not a big issue but it be nice to get it fixed.


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## saint0421 (Sep 24, 2006)

Upgrading the alternator is *not needed *but to get it checked out along with your battery. 120km on the same alternator is alot IMO. Maybe it's just time to get it replaced if it's not working to it's full potential anymore.


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## IanH (Feb 11, 2003)

I agree, but also check your terminals and clean them. sounds more like a resistance problem. If the lights brighten some on revving up under load the alternator is prob OK, but check your voltages.
Battery should be 13.2v fully charged, 14.5 to 14.7V or so when motor is running with light load and 2000 -3000 rpm.
A cheap digital multimeter is accurate enough for this (under $10)
If battery is under 12.0v when engine is off and no load then it needs to be checked. Autozone will do more thorough check on car and for free.


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## andersjs_2001sentra (Nov 17, 2008)

Hey guys, I am New to the Forum, I have a 2.0se and my lights will flicker bright then dim repeatedly... it’s very annoying. I checked the voltages and with a good load on my alternator my battery voltages steadily drop. I am guessing I need a new alternator; I have a brand new Diehard battery which I got tested. The battery is fine. Please help, I want to know What Alternator I should buy, and how to install it?
Idle no load 14.2V
Idle with Brights and heater 11.1V
Idle with battery disconnected and then turn normal lights on, the car dies. The alternator should be able to provide enough Amps with battery not connected, Right?
Any Help is greatly appreciated.
pictures would be helpfull


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## IanH (Feb 11, 2003)

It seems like you answered your own question.
Yes the alternator looks like its putting out little power.
check drive belt.
Check cables.
you can get it tested for free at Autozone on or off the car.
If you ask three people where to buy your replacement you will probably get three answers. Or more !!!
So how long are you going to keep the car ?
The alternators are not cheap, so you have to weigh the warranty vs how you feel about replacing it again if / when the re-build fails.
how do you feel about repairing it yourself ?


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## IanH (Feb 11, 2003)

BTW disconnecting the battery with the engine running is risky.... Because if the voltage regulator fails the voltage will rise till load balances the output, and you can get very high voltages, 70V or more, and this blows all the Semiconductors.....


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## IanH (Feb 11, 2003)

download the FSM at phatg20.net for free.
read up on removing - replacing the alternator.
then search here for tips problems others have had.


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## djames (Mar 10, 2008)

well i was able to replace it, it was easy once i got under, the AC gave me a little problem moving thats about it...


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## andersjs_2001sentra (Nov 17, 2008)

Anyone got recomendations for which alternator to Buy?
Thanks for the posts


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## saint0421 (Sep 24, 2006)

andersjs_2001sentra said:


> Anyone got recomendations for which alternator to Buy?
> Thanks for the posts


an OEM reman one from your nearest auto parts store will suffice plenty


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## djames (Mar 10, 2008)

i got a hitachi works great, should be the last alternator i will have to buy for the car. they should last 150k


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## IanH (Feb 11, 2003)

We brought an Autozone re-built for the SR20 and it still going strong (4 yrs ago?) W/lifetime warranty about $150 then, so other than work required to replace it if and when it fails should be fine.
Also an Autozone starter, first one lasted maybe 6 months, next one is still on there again about 4 yrs.


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## IanH (Feb 11, 2003)

other option is from the wrecker yard. around here they go for $40 and are probably as good as anything but only 30 day warranty....


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## IanH (Feb 11, 2003)

The courtesy Nissan web site says a new one from Nissan is not available...

CourtesyParts :: [23100] ALTERNATOR ASSY Part Does Not Exist - Sentra (B15U) 2000-2006


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## andersjs_2001sentra (Nov 17, 2008)

OK, I went to autozone and got everything tested. 
alternator. Tested good
Diodes. Tested good
Battery. Tested good
Current at 2500 RPM. 70 Amps.
so, what you guys think, check my battery leads?...
I am stumped
IanH, Thanks for the help


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## IanH (Feb 11, 2003)

yes, check the leads, the connectors, battery terminals for corrosion, look for any damage that may be giving you a short, this circuit is not fuse protected, so will short to ground...
and of course the ground lead, from engine to chassis or engine to battery, don't know how they did the B15.
There should be a fusible link in the alternator circuit, check that, it may be damaged and intermittent. I would suspect this as most likely.
tell me again you did check the belt and tensioner? Is it worse when it rains ?


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## IanH (Feb 11, 2003)

just had another thought.....
does this do this when you have been running for a while with a heavy electrical load, IE at night with headlamps on and maybe rear de- froster ONLY ???


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## IanH (Feb 11, 2003)

Idle under load at 11V says your battery could be weak, maybe a bad cell....
At idle the alternator normally puts out enough to run the car but no loads, the battery is used to supplement, but the advantage of alternators is the output rises rapidly with rpm, so when driving there is more than enough power, as you saw 70A at 2000 rpm.
But if the battery draws an abnormal amount of power the lights will dim. ( or a short on the starter cable as above)
So I revise my previous "most likely" to the battery or starter cables.


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## andersjs_2001sentra (Nov 17, 2008)

Checked the belts, got the battery tested and cleaned the Ground wire. I also sat in my car for about 20 min just listening to it run. The lights do there Dim bright dim thing whether it’s warm or cold rainy or dry, Large load or not. It happens at idle to 4000 RPM. I am starting to think I may have a Short or Large resistances somewhere in my Electrical system. Either that or my car is possessed and demands a sacrifice of someone’s Honda… NEW problem. My low pressure side to my A/C is leaking right above the alternator. It’s the low pressure side so I think I am going to slap some cold weld (JB Weld) on it. I got a little bit of oil leaking from the right side of the valve gasket Hmm… HELP?!!!


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