Generator current control switch

[Gary W]

I have a 1986 MCI 102A3 I had my alternator rebuilt and my not generator light is still on but I am getting 28 volts charge but my bus air is not working, the blowers are not cutting in. I bought a new Generator  current control switch but I can not locate the old one to replace. Does anybody no where it is,

[buswarrior]

 Voltage regulator?
Try up high behind a plate  in the rear luggage bay?

Happy coaching!
Buswarrior