Alternator Exciter Wire Trigger??
07-10-2007, 04:27 PM
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Alternator Exciter Wire Trigger?? I noticed that when you turn the headlight switch into the headlight full on position the PCM then sends a different voltage to the alternator via the exciter wire. My question is does anyone know the circuit/wire that triggers the PCM to let it know the lights are on so that the PCM can excite the alternator more? I want to know this so that I can take that wire and trick the PCM into thinking the lights are on all the time so that the alternator stays excited all the time since I have an underdrive pulley and the charge is weak when its hot outside and the AC is on, but if I leave the headlamps on all the time it charges good.
Anyone have a clue??
Anyone have a clue??
07-10-2007, 04:43 PM
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I can see where you are going with this but I would think that running the alt at the higher load output all time would take a toll on it's overall lifespan. That said, 99+up fbody, PCM Red connector, pin 15 is the turn on/exciter wire. It is software driven from the PCM.
07-10-2007, 04:47 PM
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It may take its toll on the alt but its an autozone one with a full lifetime warranty and its damn easy for me to swap out anyway so im not worried about that. I drive around with the headlights on all the time now just so that it stays excited anyway.
Since its software driven how can I get the PCM to fully excite it? It goes inot a full excite when the headlights are on. Do you know the wire that tells the PCM when the lights are on?
Since its software driven how can I get the PCM to fully excite it? It goes inot a full excite when the headlights are on. Do you know the wire that tells the PCM when the lights are on?
07-10-2007, 05:14 PM
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Why not just check PCM red connector PIN 15 output? Use a voltmeter and check for what voltage you have at that PIN with the headlights off, then on, then unplug that wire from the computer harness and apply whatever voltage the PCM was applying to that wire to excite the alternator.
07-10-2007, 05:23 PM
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Originally Posted by Doc
I don't know if any of the major software support companies offer any control of this parameter. Why not just get a more powerful alternator?
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07-10-2007, 07:01 PM
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Well hopefully its like 12V when fully excited, that way ill just run ignition switch power straight to the alternator. I suppsoe I could get a high amp alternator instead though. Well see.
