How can I fix my interior fan heater?

first check the fuse,
if it's good (fit another one as they can fail without looking bad)

next you want to check the connections at the motor, put the heater controlls to fresh air in (i.e. opposite end to recirculate)

pop the bonnet, then look in the heater box, you should see 2 wires with push on connectors joining the fan motor, quite common for the connectors to corrode and fall off,

if they are on, using long nosed pliers, remove one and see if it's tight and clean, then try the other.

have a look at the comutator, is it filthy or shiney copper?

then using a multimeter, check for power at the motor, if no power, then remove the resistor pack, it's in the right hand side of the fan box, pull the white multiway plug out, then a couple of screws and pull it out, check for burnt resistors, or more commonly the overheat cut out being stuck open.

if it's stuck gently re-position it so it re-contacts, then put it back together.

if still no jot, then check the switch, again with a multimeter.

Gazz
April 2010