Wiring help with HO Alternator Please!!

[CTScott]

Originally Posted by Yaris Lighter

Ok Scott I need your brain again!! After a closer look at the wires on the HOA, I found a 4th pin that didn't have a wire to it. Seems like they just wanted to use three wires. So I was able to rig it to where I then had 4 wires. But now... the "fun" begins.
After days of working on cutting pieces of the HOA, finding new bolts, extending wires and all that jazz I was eventually able get the HOA on and in the right place so the belt wasn't slipping off and able to spin all the wheels correctly. I hooked up all the wiring and everything seemed great but my Idiot Light was on when I started the car. I wasn't too worried at first because I have a digital gauge + terminal and the voltage was reading at 14-14.5 for a good 5-7 minutes so I just figured oh well and happy day. However, after starting the car up a second time the voltage on the gauge wouldn't go pass 12.1. It would fluctuate at 11.8-12. I turned the car off and on again with the same results. I hadn't touched anything from when the gauge first read 14+. So I pulled out my multimeter and thought maybe a connection came loose on my Voltage Regulator wiring but this is the readings I found:
S wire 11.8 v
I wire 11.8 v
L wire is only at .9 v (causing the idiot light I bet)
Lastly the M wire (the one I rigged) is at 5 v

Do I need to switch or combine some of the wires? I have them all in the right places I thought. I followed what we had discussed before so IDK what to do or what changed from the first time I turned the car on after hooking up the wiring. I’m going to unhook the M wire I assembled to see if that changes anything. Maybe the pin was unused for a reason=D. Please let me know what you think and thanks for all your help Scott!

My bet is that the alternator is generic, so I would not hook up the extra wire to the M terminal unless the alternator manufacturer can confirm its purpose.

I would also not move or combine wires. They are labeled, so verifying that the labeling is correct should be done with the manufacturer as well.

The low voltage on the L wire does explain the idiot light not working. The low voltage on the second run almost makes it sound like something already failed within the alternator, since you are reading battery voltage, rather than a higher output voltage from the alternator. Check the two large fuses on the positive battery terminal red plastic chunk to make sure one of them did not pop.