Auto Air Conditioning & Heater Repair: ford ranger air conditioner, Fan speed only blows on max

Question
the fan on the air conditioner has stopped working it blows on number 4 but not on 1 to 3, the light for air conditioner is on as normal

Answer
Sounds like the rheostat on the heater box
This controls the voltage to the fan in 3 6 9 & 12 volts stages.
When you set it to fan speed four this bypasses the rheostat and give the fan 12 volts to blow on maximum
Look under your glove box upwards from the passenger footwell and find the fan housing, it is likely to be cylinder shaped and houses the evaporator and heater matrix
Look for two or three wires that go in to a plug. On the Focus we have to remove a cover but it will be there somewhere.
Once you have found it it is a really easy job,

New one from Ford shouldn't be more than £ 20.00

Thanks