Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Loss of heater fan speed

Dave, Be thankful you don't have the earlier push button sequential switch which adds a logic control level to an even larger and seemingly more unreliable PCB!

It seems highly likely you have a two speed system so fixing the fault would be easiest option. If you are handy with a voltmeter it should be easy to trace.

Asssuming no wiring or connector issues the chain of fan control is Switch -> PCB -> Motor. The switch as Rog suggests may be a good starting point. If your car has same switch/PCB as shown on Rog's pic, all the switch wires are red, but one will be live with ignition on selecting one or other of remaining two according to low or high position.