Alternator not working after PCM swap, HELP

[edwardzracing]

So I swapped over to a 02 PCM and did the pinout swap on my 98 Camaro. I also put in a new wiring harness as well. So now that the car is running again, my alternator doesn't work. Anybody have any ideas on what I should check to diagnose this? Really has me confused. What wires control the alternator at the PCM? Is there a fuse that may be blown somewhere? Any help would be greatly appreciated. Thanks!

Brad

[joecar]

Hi Brad, the alternator has a turn on wire which is powered by the PCM... check that you have this connected and what voltage is on it (using a DMM).

[mr.prick]

IIRC 98's have 3 wires to the alt '02 has 1.

[edwardzracing]

Hi Brad, the alternator has a turn on wire which is powered by the PCM... check that you have this connected and what voltage is on it (using a DMM).

Hey Joe, thanks for the response. Would you happen to know what wire this is on the PCM? Is this the red wire that gets deleted in the PCM swap or is there another wire that I moved from one spot on the 98 pcm to a new spot on the 02 pcm?? I just don't know what wire to check and can't find anything alternator related in any of the pin out lists that I've found online.

My luck with this car is next to zero... it hasn't moved in months. This sucks. Thanks for your guys' help.

Brad

[mr.prick]

LS1 Swap FAQs

[edwardzracing]

LS1 Swap FAQs

Yeah, I know about that thread... unfortunately I can't track down what pin on the 98 PCM controls the alternator... if I knew that, I could then refer to the swap info and see where that wire goes to on the later PCM's. Hopefully it's just a loose ground wire or something stupid. I love electrical issues

[joecar]

Have a look at these circuit diagrams...


(VIN G = LS1)

[edwardzracing]

My alternator had one red wire on the plug. I'm hoping that's right. Pulled the alternator and had it tested... and it works, so I know it's a wiring issue on my end.

[edwardzracing]

Have a look at these circuit diagrams...


(VIN G = LS1)

I'm all sorts of confused. Should the wire that plugs into the alternator have 12 volts or close to that with the ignition on? And where the hell does that one wire go to?? I HATE WIRING PROBLEMS!!

[joecar]

Your 1998 red wire to alternator L terminal should be working....

red wire runs from instrument cluster pin A14, thru connector C220 pin A, and then to alternator L terminal pin B;

check that it should have approx 10V on it since the 470 ohm resistor drops battery voltage;

check fuse 9 in fuse panel next to instrument panel (on the left of, next to driver door hinge).