Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

alternator operation


  • Please log in to reply
10 replies to this topic

#1 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 13 April 2011 - 12:31 PM

93 legacy sedna 2.2 at. the alternator has four wires total going and or coming from it.

the main wire comes from the battery and is hot all the time. this is the exciter side of the alternator. i think.

then in the plug of the alternator are three other wires. white black and yellow. thw white with key on engine off has power going out of it through the alternator. the black wire goes to the charge light. the yloow wire is suppose to supply power to a diode and then from the diode supply poiwer to the iginition relay.

is this yellow wire suppose to also be hot with key on and engine off? and is it suppose ot be a full 12 volts?

#2 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 13 April 2011 - 05:53 PM

ok i was finally able to get the belt on. and tried to start it. i got the same thign. no power coming from the alt on that wire. so i took the alt i had been rebuilding (new diodes new brushes) off and took it to the parts store. the alt failed to pass. i cant believe this alternator keeps falling apart or not working. this has been the problem from the start. i guess i am just going to buy another one. i am done trying to replace parts in this one.

#3 danbennett2u

danbennett2u

    Subaru Fanatic!

  • Members
  • 500 posts
  • Longmont CO

Posted 13 April 2011 - 06:06 PM

I personally would get a OEM one from a junkyard rather than one from the auto parts store, I have had very bad luck with remans from other manufacturers (replaced one on a grand prix years ago 3 times within a year)

of course what you find in a junkyard may be a reman as well, but all of the subarus i have owned so far seem to have their original alternators and have worked fine.

#4 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 13 April 2011 - 06:17 PM

i'm not doing the parts store thing for sure. edit: wht is the finned thing inside the alt that the plug plugs into? its not a rectifier. what is it called?

#5 GeneralDisorder

GeneralDisorder

    Elite Master of the Subaru

  • Members
  • 20,281 posts
  • Portland

Posted 13 April 2011 - 07:33 PM

The module inside the alt is called the voltage regulator.

The yellow wire goes to the ECU. I can't recall its exact operation.... IIRC it's something to do with fuel pump control.

GD

#6 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 13 April 2011 - 07:58 PM

it failed a test at another part store. . so i am wondering if the voltage regulator bein bad would cause a complete fail. i dont know why i didnt think of it being called that. because a voltage regulator tells the alternator how much to charge. anyway thanks for the replies. i am goign to call the junkyard tomorrow and see what i can get a used one for.

#7 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 20,058 posts
  • WV

Posted 14 April 2011 - 06:50 AM

they're cheap - used should be $20-$50 tops.

1996 (or 1997) Subaru Outbacks (EJ25's) I think have the recall and therefore you can buy them new from Subaru for only $60-$75. that's so cheap i just bought one as a spare. many alt's interchange, maybe that will work for you.

#8 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 14 April 2011 - 09:43 PM

the only one i could find close to me was a ac delco reman on a 94. for 35.00 i passed on it. but i am now going to go back and get it. i sure hope the mother flocker works. i am not sure i trust the place. i think i am going to ask about a warranty from them.

#9 ShawnW

ShawnW

    Subaru Master Technician

  • Administrator
  • 12,941 posts
  • Denver, Colorado

Posted 15 April 2011 - 12:21 PM

they're cheap - used should be $20-$50 tops.

1996 (or 1997) Subaru Outbacks (EJ25's) I think have the recall and therefore you can buy them new from Subaru for only $60-$75. that's so cheap i just bought one as a spare. many alt's interchange, maybe that will work for you.


The harness plug for the Outback Alternator isn't round like the older Legacy one.

I can ship you an alternator if it comes to that.

#10 General chaos

General chaos

    USMB is life!

  • Members
  • 206 posts
  • Missouri

Posted 15 April 2011 - 12:26 PM

my plug is round.

#11 Cougar

Cougar

    Elite Master of the Subaru

  • Members
  • 6,340 posts
  • Anchorage

Posted 17 April 2011 - 10:27 AM

The main wire of the alternator tieing to the battery is the output wire, not the exciter wire. The wire tied to the warning lamp in the dash should tie to the exciter. The lead supplies power to the exciter through the warning lamp and then when the engine starts the exciter builds a charge up in the field windings of the alternator. When field builds up the alternator starts working and also backfeeds a voltage on the lamp wire. That causes the warning light to turn off when the alternator is working correctly. If there is a problem then that voltage drops and the warning light turns on. That circuit is also tied to the warning lights and is how they are tested when the key is turned to ON and the engine OFF.

Another lead on the back side should tie to the regulator so it can monitor the charge state of the battery.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users