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EJ22 to EJ25 alternator swap?


scoobyclimbs
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Given my ej22 alt . is only 70amps , not enough with all my overheads running..

 

I looked at the ej25 alt. which have 85 or 110amp outputs..

the only difference is the plugs.

 

the ej22 has a 3pin and the ej25 has a 2pin.

 

So my question is how to splice it in to the ej22 harness..correctly?

 

Has anyone done it successfully?

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The large wire of the 3 plug type is mearly a splice off of the main battery feed that bolts to the terminal. Literally the wire goes about six inches back into the harness and is spliced to the big power lead.

 

In the 2 plug I believe the connection is made internally, so just eliminate the big wire and splice the other 2 (yellow, through diode to ECU IG., BW to charge light in your original harness)

 

Someone correct me if I'm wrong but this is my first thoughts.

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  • 3 weeks later...

70 is pretty decent for a couple extra lights. I wouldn't run more than like 4 off it though. The stock alt's are designed to handle a larger stereo, CD player, small amp, as well as the optional fog lights that were availible through the dealer - all that is optional equipment designed to run off the stock alt. You should be fine if you are just running a single extra set of lights.

 

If you are running with all the options, and two or more sets of lights, huge stereo amp, etc then a 90 or higher would be a good idea.

 

Just remember that the main output wire from the back of the alt to the main junction as well as the juntion to posistive battery terminal should always be upgraded in addition to any circuits you are going to add for lights, etc. If the battery is drained it will draw as much current as the alt can give and if the stock wiring is built for a 70 and you install a 110 - you now have the potential to pull 110 Amps to the battery. The wireing may not like that.

 

GD

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Good points to consider...though, the wire from the alt to the battery is pretty short - shouldn't offer much resistance.

 

Resistance isn't the problem.... well it is in a way. Max current capacity (ampacity) of the wire guage is the problem. Maybe it just causes a bit of heat at 110 amps through the stock wire - but if there is any kind of corrosion or a loose connection - 110 amps might well cause a fire where 70 did not. Could be borderline and I would run a second wire to supplement it just to be safe. 110 amps is a LOT of amps. Don't mess around with that much juice.

 

GD

Edited by GeneralDisorder
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