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ej 25 alternator wireing
farquire - September 13th, 2014 at 09:03 AM

have the motor in my syncro and running,close but no cigar as yet,its putting out 15.6 v is this too high, alt light is on all the time,have the three wire plug alt black/white to dash light where do the other two wires go, blue/red and black/red also the engine check light should this come on with the ignition and go out once started carn't get it to do anything at the moment
mike


Joel - September 13th, 2014 at 01:28 PM

Is it a late model engine?

the later alternators are controlled by the ECU as they dont start charging till the engine is upto temp.

there is generally a warning light wire, ECU control wire and voltage sense wire.
Black/white is normally warning light, how have you hooked the other 2?


farquire - September 13th, 2014 at 05:42 PM

its a 2003 liberty motor the other two arn't connected


mackaymanx - September 13th, 2014 at 06:32 PM

This is the label off a 2003 Liberty alternator on the motor I pulled last week.

L - Light
S - Sense
C - Computer

from what I've read leave the C terminal unconnected and it will self regulate.


mackaymanx - September 13th, 2014 at 06:36 PM

This is exactly the same as the 2005 Liberty alternator. If you hook up the C terminal to power, the alternator will put out 20 volt ( first hand experience with this).


Joel - September 13th, 2014 at 07:00 PM

Quote:
Originally posted by farquire
the other two arn't connected


there is your problem, the sense wire needs to connect to the battery positive so it knows what voltage to put out to maintain proper voltage at the battery.


farquire - September 14th, 2014 at 09:49 PM

connected up the sense wire light went out but is out all the time now unless i earth the light wire manually to check the bulb,the black and white seems to have 5-6 volts all the time motor running or not ,i thought it would be negative untill the motor started and alt charge changed it to positive and the light goes out,thats my basic understanding of it,if its negartive all the time the light stays on positive all the time it won't light,have another alt i can try later in the week hopefully it won't do the same thing


farquire - September 17th, 2014 at 09:59 PM

changed alternator all is good, charging at 14.6,dash light goes out as soon as it starts,black and white is light ,blue and red is the sense wire,third on mine is black and red and doesn't appear to be needed,one step closer to driveing it