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Introduction- You should be able to remove alternator without removing anything else as long as you remove alternator from bottom. You will have to remove the cover that protects bottom of engine if it is still in place. I would say this removing alternator is pretty easy.

Buying alternator:

The best price is likely from a shop that specializes in rebuilding alternators and starters. listed under auto electrical in phone book. There is normally a refundable core charge. you could also try junk yard if you are short of funds. Ebay seems to have very good prices.

Procedure for removing

1. Disconnect the negative battery terminal.( VERY IMPORTANT IN THIS CASE)2. Disconnect black wire at (labeled m)alternator with 8mm wrench. Disconnect white wire with 10mm wrench(labeled battery). Unplug the main alternator plug.(squeeze to release)3. Back off the tensioner bolt a bit to give yourself some room. Use 14mm socket and access from the top.



4.Completely remove the bolt that connects tensioner to alternator. Your tensioner will now be dangling a bit.(access from under car)





5.Completely remove the pivot bolt with 14mm socket (access from under car). There is an odd shaped nut at the other end. The bolt only threads into this nut and passes through alternator and alternator bracket without any threads. You will need to use a small locking pliers on bolt and hit with rock to get bolt out. The lower fan shroud will get in the way a bit but you can do this without removing shroud.



6. I used a small rock to bang the alternator off the alternator bracket. The alternator than comes down through the bottom. You have to twist the alternator to steer it out to freedom.

7. Reinstall is reverse of uninstall. Use a screwdriver to help align the hole for pivot bolt. clean pivot bolt so it slides easier.

End of removal instructions



Description of pivot bolt and tensioner:

There is a 14mm bolt at bottom(alternator pivots on this bolt) and the two 14mm bolts associated with tensioner at top. The bottom bolt(pivot bolt) and the bolt that locks tensioner to engine , face front of car. The bolt(long bolt) used to adjust tension is accessed from passenger side of car.

You dont need to pry the alternator to tighten it. Tightening the tensioner will tighten the belt. Once you have tightened the tensioner, the alternator is fixed in place. The pivot bolt and the tensioner locking bolt can be loose and the the alternator will still be fixed in place.

IMPORTANT you have to back off the tensioner and loosen the pivot bolt and tensioner locking bolt before alternator will move to allow removal of belt. Three things to loosen before the alternator is free to move!

Belt deflection specs:

ALTERNATOR:-belt deflection with engine cold mm(inches).....max limit 11 (0.43) .....adjusting used belt 7-8 (0.28-0.31).....new belt 6-7 ( 0.24-0.28)

pivot



top of alt

Alternator bracket. One per car of course. bracket is connected to engine. You can put end of hammer handle on square nut and push the alternator back to tight position and vice versa.









from 1991 factory service manual

Note that there are two types of alternator so confirm which is for your car:hitachi Alternator

Mitusbishi alternator



Links

alternator testing

http://jgdarden.com/batteryfaq/carfaq5.htm

bolt sizes

pivot bolt- M10x1.5x100. Same bolt that secure the A/C compressor the bracket.


Modified by vancouverbc at 9:39 PM 1/2/2010

Great write up. I've been thinking of swapping out my alternator and wasn't sure how hard it would be.

fromeast2west wrote:Great write up. I've been thinking of swapping out my alternator and wasn't sure how hard it would be.

thanks

Added some pictures.

Awesome Write Up.

Contact d!ck OR FlatBlackIan.

So We Can Get This In 240 Tech.And You A Custom Title.

OG Members FTW!

This tutorial will be located with other tutorials in the Nissan Online Mechanic section- Index of all Tutorials There is a lot of good info in there...check it out

I was doing my alternator today and i wanted to add because i feel like its not 100% adaquate. Ok so i tried using my alternator off of my 97 motor and use it on my 91. Well lets just say even though it bolts right up and technically should be for the same motor its not. I tried to modify the battery connection and the harness plug but it didnt work. My battery light turned off but it wasn't charging the battery at all. So i picked a new one up and started all over again. I wanna add a little more for a better understanding on what else is needed for the removal of the alternator while its still in the car. For starters you cant just remove it from the bottom because the sway bar is in the way and if you try to go up and forward your fan and shroud get in the way. So to make it a easier i loosened up the power steering then i removed the intake. I then proceeded to remove the shroud then the clutch fan. Its probably more tedious this way but less stressful for me. Its best now to disconnect the battery and the harness plug and the ground if you haven' t already. Next i started to loosen up the alternators tension bolt then i unbolted the top bolt then the bottom bolt. Once you got them off try to move it to loosen it because chances are that thing is in there tight. Once you've got it loose enough to spin it rotate it counter clockwise so it will spin off the mounting brackets. Now this is where it got a bit tricky for me. Trying to pull it down seemed the likely route but there wasnt enough room to pull it down. So thats where that whole removing the other stuff comes in. If you can try and twist it a little so you can pull it down and towards the right, in front of the engine. If you played you cards right you should be able to pull it up and out after a little maneuvering. Once its out make sure everything looks identical between the two alternators. And to install do steps in reverse. I hope this helped because when i read this the other day it wasnt very clear about certain things. If i left anything out please feel free to add.

Thanks very much. I'm having such a hard time getting that alternator out. did you you have to remove anything else besides the plastic cover?

JCMITO wrote:Thanks very much. I'm having such a hard time getting that alternator out. did you you have to remove anything else besides the plastic cover?

it takes a bit of trial and error. ive never found anything mechanical easy. didnt remove anything else .

If there is a short in the 2 pin plug would it keep it from charging?

Where are the best locations to check for charge and problem shoot?

(changed the alt the thing still wont charge, or at least not enough, would like to check for volts AT the alt. and see if its being lost somewhere along the way, but I am worried there might be a short in an old splicing job on down the line from the plug...)?

Mr student, did you check the age of the thread you bumped?

Best bet, get an alt from a Nissan Quest, same size, same plug. much more output, same cost if not cheaper. Only thing you need to do is drill the mount hole on the alt a bit as the bolt for a 240 is thicker.

If the alt isnt charging well, maybe you have something drawing energy? There was a new alt on my 240 when i bought it, but the fender was dented in just enough to block the path of the headlights going up and down. So as the motor tried and tried, it just killed my bat.

No, sorry, I had searched it out on the tutorial side and never checked.

One of the first things I did was change the alternator, but still no charge. It only drains when the key is on or the car is running, not a slow constant drain.

It is a new issue, I have searched high and low for around 12 hours total trying to figure this out. Its killing me and nobody around seems to have any ideas

IF one of the wires which run from the plug are shorting out would this cuz such an issue? I figured they are responsible for the battery and charging lights but didn’t know if they would effect charging in general...?

Volts from the alternator are only reflecting the battery volts (as the battery drops the alternator drops as well).

I don’t remember if this is normal but, when i turn the key and the dash warning lights come on - the battery light does not show. Is that normal? Or is my light failing to light up?


PLEASE help

Got it! kinda...

It was faulty wiring from the 2 pin plug. And your battery light will not come on if there is an issue in that wire/plug.

Sadly it will no longer turn over via the key. I have a remote start and it works fine though.

Its charging again (with more juice than ever, used an SE alternator). Sadly I have not found the key issue.

No more custom titles... but I will ask for article