I've got an m1008. Gen 2 is getting 24v on the red wire in the back, but nothing on the brown when i turn the key. gen 1 is working properly. both dash bulbs are good. I've been trying to trace the brown from gen 2 to make sure the wiring is good, but i'm having trouble finding it where it goes through the firewall. Where does it go right when it passes through the firewall? thanks
Here is the diagram with the GEN2 exciter wire.I changed the wire color to green to see it better. First thing to do is check the very bottom 24v fuse. If it is bad GEN2 won't work. And the GEN2 relay must be working.
Current flow is : fuse, GEN2 bulb, relay, diode, firewall and then the alternator plug.
The brown wire comes thru the firewall and is part of the large wire bundle and works its way around the back of the engine and then to the alternator. The thick RED circle is the GEN2 terminal (ignore the thin red circle - it is a left over from another issue)
I'm sure you have read the first few pages of the troubleshooting section of the TM 9-2320-289-20 tech manual. It tells you how to read the diagrams and what all the wire labels and diagrams mean.