I followed the wiring instruction from a new bathroom fan with a heat lamp. The old one worked with two switches. One for the fan and one for the heat lamp. After installing the new one this is what it does.
When I turn on the switch for the fan, the fan works and the filament in the heat lamp glows just slightly.
When I turn on the switch for the heat lamp, the lamp turns on normally.
When I turn them both on, only the heat lamp comes on.
What could be wrong?