05-30-2014, 11:38 AM
Join Date: Jul 2012
Total Cats: -2
NA alternator swap issues
Recently I put an NA alternator in my NB MSM due to my MS2 freaking out about controlling the alternator and spiking voltage and I was tired of dealing with an ecu controlled alternator. I followed Jeremy at FM's instructions on putting it on my MSM
These are the instructions I followed :
Start by disconnecting your battery so you don't short something out. You also might need the harness pigtail for the 94-97 alternator.
- The big white wire is the same for both units.
- There's a 2 wire plug in the 04 alternator with a grey wire, and a grey / red wire. Cut off the 04 plug, and splice the grey wire into the white / black wire of the 94-97 pigtail. Next splice the grey / red wire into the white / green wire of the early pigtail. Plug it in to the alternator when finished.
We have to move these wires, but we'll do it at the ECU plug (under the dash, by the steering column) where they're easier to get to.
-The grey / red wire goes to 3M at the factory ECU plug. Cut it off, and splice the harness side of the wire into a switched 12V source from the main relay.
-The grey wire goes to 4T at the factory ECU plug. Cut it off. Also cut off 3U (brown / red). Splice together the harness ends of 4T & 3U. The ecu will no longer be controlling anything with the alternator and you should now be seeing 13V continuous.
My harness was exactly the same as the NA alternator, the gray and red was where the green and white was. I supplied the 12v switched from the ignition switch because I had previously had a wire hooked up to it (checked all my continuity and resistance of the wires in the alternator circuit to ensure it was fine)
Problem is, the gray and red doesn't charge the alternator (I'll see 12ish volts) but it makes the relays freak out clicking. I swapped it to the gray wire, and it charges the alternator (ill see 13-14.9), but my fan relays and AC relay do not work. I verified it was getting the 12v switched with both wires. It's odd how the alternator seems backwards, but even more odd the way the relays are acting. It's extremely odd that it even effects the relays as the alternator is on its OWN circuit now.
Anybody have any input? I'm pulling my hair out over this.