My sense wire is constant hot, it should have direct connection to the battery to correctly adjust voltage. Your alt must be differant.
Edit: I was just thinking, the switched power isn't for the sense wire it's for the charge light wire, that is what activated the feild windings in the alt to make it charge, this needs to be hooked up through the charge light to work properly or you need to wire it to a switched hot with the correct resistance. If you wired your charge light wire straight to a 12v power source, that could cause the internal VR to burn out and creat a dead short that will kill you battery. I did that the first time I tried the swap in mine.
No you are wrong Mikeleda.
The Charge wire and the sense wire on 90-94 EJ alts are 2 seperate circuits.
Charge wire is White/red in the EA cars. IN an EJ swap you do not need to do anything except connect this White/red wire to the terminal that the B/W wire on the EJ alt used. DO NOT give 12v to that line direectly. If you measure voltage while disconnected on that wire with key ON you get a bit less than 12v, but that is only because the 12v is passing through the lamp, trying to get back to ground. That wire isn't actualy providing the sense function. It does serve to excite but won't surfice for regulation.
You need the sense wire that was originally yellow in the EJ cars. On early alts this needs to be switched power.
The sense wire is indeed tied directly to the same yellow wire that supplies the ECU with IG. switched Voltage.
Later EJ alts eliminated this Yellow wire, and tied that function right into the Battery line. I believe though that these alts are diesigned to function this way so they don't drain batteries like the early ones would if hooked up all the time.
Edited by Gloyale, 07 May 2013 - 04:12 PM.