Alternator not working after PCM swap, HELP

[edwardzracing]

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).

Okay, fuse 9 (Gauges) was fine. No voltage on red wire with key in the on position. Looks like I'm really screwed now. Is there another fuse somewhere in the engine bay that might have something to do with it?

When I swapped over wiring harnesses... could there be a ground wire for that red wire that's loose somewhere or not making good contact?? Wow I'm lost. This really sucks. Thanks for your help, Joe.

[edwardzracing]

I'm going to trace the wire into the interior and see if there is any voltage in there with the key on. I'm guessing connector C220 is the connector just inside the interior on the passenger side where the engine wiring harness comes in through the firewall, yes? I think I remember there being two connectors there, so hopefully one of them is the C220 connector. I'll try to track it down tomorrow and post back with the results. All the gauges are working. I'm beyond confused.

[edwardzracing]

Quick update... I have voltage in the interior after the C220 connector on pin a, so somewhere along the line out to the alternator it has a break or something 'cause there's no voltage out there. I'll see what else I can find.

[joecar]

Does fuse 9 have voltage on both ends of it...?

If the voltmeter works on your instrument cluster, then the problem will be where you said: connector C220 and/or passthru P110.

Locations:
C220: Instrument panel to engine harness, under the right side of the instrument panel, behind the knee bolster, see #8 in first doc.
P110: Right side in the dash panel, engine to the passenger compartment, see #8 in second doc.


1998 Chevrolet Camaro




(01)C240
(02)Instrument Panel
(03)Cross Car Wiring Harness
(04)Right "A" Pillar
(05)Dash Mat
(06)C210
(07)C230
(08)C220
(09)C219

1998 Chevrolet Camaro

1998 Chevrolet Camaro





(01)P100
(02)Forward Lamp Harness
(03)Battery
(04)C102
(05)C100
(06)C105
(07)C101
(08)P110
(09)Engine Harness

1998 Chevrolet Camaro

[edwardzracing]

Pictures aren't working for me. Voltmeter is definitely working on instrument cluster. I found the wire at C220... unhooked it and checked it... voltage. Hooked it back up, checked the wire right after the connection... voltage. There must be a break somewhere 'cause there is no voltage at all out at the alternator. That isn't going to be easy to track down either... would I be safe to run a new wire?

[joecar]

You could run a new wire for now (that's what I would do)...

and eventually one day when you have free time on your hands find/fix the break.

[edwardzracing]

You could run a new wire for now (that's what I would do)...

and eventually one day when you have free time on your hands find/fix the break.

Thanks Joe... really appreciate your help!

[edwardzracing]

Ran new wire, now have voltage at alternator clip... will get alternator put back on and hopefully report back with a charging battery Thanks again!

[jetblast]

looking at that schematic, your problem is somewhere between the pcm blue cconnector pin 61 to connector 220. you definitely need to verify which pin is used on that pcm to begin with, but assuming the schematic is correct, do a visual and make sure the pin is in place, at the blue connector pin 61 and also check for power there. that wire, which should be brown is only used to excite the field, so don't be concerned if it only reads 5.volts. if you have no power with the ignition sw. on, then you have to trace the wire by disconnecting the battery first, and then put a continuity mm probe on pin 61 to the gen. connector pin b. keep in mind that, that connector, according to the diagram has 2 wires both of which meet there, so you have to separate them or disconnect connector 220. if you have continuity at the brown wire circuit 25 and you are absolutely sure that there is no break between pin to pin then i would suspect the pcm. good luck!