The fan heaters in my car are only blowing cold air and its rather cold just now so id prefer to get some hot air.Ive tried to bleed the system incase it was air locked but that aint worked.Any ideas? could a resistor have failed or a switch?

 

thermostat [not fitted] or blocked matrix

 

disconect the two pipes going into the heater matrix at the blulkhead just above the exhaust port for #4 cylinder
connect a garden hose with a water supply to one outlet on the bulkhead and another piece of garden hose to the other outlet,
put the heater control to full heat (no need to have the ignition on for this) and turn on the tap slowly and see if you get a good flow through the matrix if not make sure that the heat control cable has not come off the valve that controls water going into the matrix (it buried down there somewere) if all that is ok then check the stat is in place,or which ever you want to do first

 

Cheers I will give that a go.