Pilot light and indicator (light) are both terms for the same thing, so they should be interchangeable. I do not know if the power windows switch will work for a start key. My guess is that it wont since power window switches are usually momentary and start (power) switches are usually maintained switches. The run away motor problem and momentary non-operational issue are usually caused by bad connection and or short circuits. I recommend soldering all cut and spliced wires, and soldering wires to the terminals that are inside of the connectors. Wire connections that are not soldered tend to be unreliable in vehicles due to vibrations operating the vehicle causes.
Is the indicator connector the same as pilot light connector on old controller? Will the power windows switch work for a start key? The motors will sometimes continuously run full blast without pressing the gas pedal then quit for a while. Other than that it won't run, do anyone know what this problem could be?