V6 Alternator Upgrade DIY W/ pics

Discussion in 'DIY - Do It Yourself Forum' started by nixed007, Jan 29, 2009.

  1. dorkiedoode

    dorkiedoode Well-Known Member

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    pour water in it
     
  2. PSPEC

    PSPEC New Member

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    I have been doing research on this subject since I have a 1997 Honda Accord with 4 CYL. F20B DOHC VTEC swap.

    What I know so far is that the 4 CYL. versions of these cars

    1990-1997 Accord
    1998-2002 Accord
    1997-1999 Acura CL
    1992-1996 Prelude
    1997-2001 Prelude
    1995-1998 Odyssey

    All use Denso Alternators, some are 80 AMP some are 90 AMP and they are all physically the same size. The pulleys might be slightly different diameter, and the plugs on the older ones are big and round and the newer ones are small and square. All the wires are the same color and the same orientation. They are all CCW rotation

    V6 Hondas spin CW unlike the older B, D, F, H series honda motors which spin CCW

    The newer V6 alternator CAN be made to work on a 4 CYL H or F. Its physically the same size so it will bolt right up. The belt tensioner can take up the slack if the pulley is slightly different in size. It has the smaller square plug so 97-01 preludes and 98-02 Accords it will plug right in. Older Accords / Preludes can swap plugs on the harness.

    An alternator does not care which way it spins. You can spin it CCW or CW and still make the same power. The only thing that can pose an issue is the internal fan that is inside the alternator. This fan blows air accross the heat sensitive components in the alternator. Alternators get hot when they make electricity. This fan is on the spinning alternator shaft and needs to blow air in the proper direction to cool the correct side of the alt.

    I'm not sure if DENSO alternators have a fan that will blow in both directions. From the pictures I've seen it looks like the blades are actually reversed from CW to CCW.

    All you would have to do in this case is take your alternator fan from the inside of your Accord or Prelude alternator and swap it into the Alternator from the Odyssey. Now you have a 130 AMP CCW Odyssey alternator

    For me, I have a 80 AMP alternator on 1997 ACCORD. I am putting in some beastly SPAL radiator/AC fans from a maserati that draw 40-45 amps when they are both on. I'm worried about my alternator not keeping up when the A/C is on and the headlights are on and the radio is on etc. The 130 AMP alternator from the 99-01 ODYSSEY seems to be the perfect solution for this problem. It compensates for the amps that my fans are going to use and even adds some extra.

    Reason to get this instead of an aftermarket alternator that is "high amp"?

    Its OEM Denso / Honda. It will make 14 volts at idle-unlike many "high amp" aftermarket rebuilt alternators that don't make **** for volage untill you rev them up. Which is useless for my situation since I want my A/C fans to be on and my A/C cold at idle.
     
    Last edited: Jul 1, 2010
  3. PSPEC

    PSPEC New Member

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    you should read the above post too.
     
  4. PSPEC

    PSPEC New Member

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  5. PSPEC

    PSPEC New Member

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    It appears that DENSO alternators have two internal fans, there are fans on either side of the alternator rotor. Hopefully they are held on with screws

    EDIT: I just took an Accord alternator apart and the fans are spot welded in place. That pissed me off. So...

    I also checked hondaautomotiveparts for diagrams of the 94-97 Accord alternator and the 99-01 Odyssey alternator to compare. The fan blades are turned in the same orientation even though one spins CCW and one CW. This means that DENSO used alternator fans that can cool in either direction depending on which way you spin the alternator. So I think I can just bolt the Odyssey one on. I will also upgrade my alternator to battery charge cable to 6 or 4 gauge wire.

    94-97 Accord 4 CYL (80 AMPS)
    http://www.hondaautomotiveparts.com...R)&catcgry4=KA5MT&catcgry5=ALTERNATOR+(DENSO)

    99-01 Odyssey 6 CYL (130 AMPS)
    http://www.hondaautomotiveparts.com...gry4=KA4AT&catcgry5=ALTERNATOR+(DENSO)+(-+01)

    If you upgrade your alternator don't forget to upgrade your alternator-battery wiring! If you don't you can have low voltage and your wires can get hot and melt and possibly catch fire!
    http://buickthunder.com/FAQ Alternators.doc
     
    Last edited: Jul 2, 2010
  6. crookx

    crookx Member

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    nothing to see here
     
    Last edited: Jul 10, 2010
  7. slaiguy

    slaiguy Well-Known Member

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    $380 for an alternator? theres gotta be somewhere to get 'em cheaper...
     
  8. Garcia61904

    Garcia61904 Well-Known Member

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    Great DIY.
    I just did this upgrade yesterday and no more dimming when I put windows up or turn signals or any little source of power consumption.

    No dimming when I turn up the sound system. Very slight dimming when sound system is turned up and power up the windows but it's too loud so I wont be listening to it that high anyway it was just for test.

    Car starts up faster.

    Great upgrade for cheap.

    $75 at the junkyard 1 month warranty
     
    Last edited: Jul 15, 2010
  9. Nguyen916

    Nguyen916 Well-Known Member

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    PSPEC did you ever find out if the alternator works on the 4cyl?
     
  10. Cord_Sleeps

    Cord_Sleeps Member

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    Very nice DIY, for those of you who are switching alternators to increase the AMPS from 105 A to 130 A OR 80 A to 130 A you have to realize your still limited unless you change the 100A fuse stock under the fusebox for the V6 and 80A fuse stock on the i4. :peek::
     

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