Look up under the outside cap, on the passenger side, with the genset slide out, on the bulk-head, near the top, below the windshield/dash. But not sure what you are describing is a resistor pack issue, except maybe the plug-in/connector. Sounds more like fan motor or the control knob on the dash....but resistor pack is common and cheap-try it.
2003 Alpine 40' MDTS
New Braunfels, Texas