Winter so lots going wrong. The Legacy has an aircon delete by previous owner, but heater fan has always worked well. Just cold air now. Engine coolant level bang on maximum. Checked relevant fuses ok. Presume an element failed somewhere. I am told the main circuit board on these have a tendency for the solders to fail if anyone has any experience?

 

What makes you think heat is supplied electrically??
The "blower fan" electrics usually has a resistance coil pack to regulate the speed - that is all. (Manual - resistance pack; Auto - power transistor and electronic control unit)
The heat is removed from the engine coolant via a heat exchanger through which the cold air from the blower passes.
Temperature is controlled by mixing air that passes through the heat exchanger with cold air direct from outside.


You may possibly have an air mixer flap actuator motor failure/broken link/disconnected link, or an air lock/ blockage in the heat exchanger coolant circuit.




Without knowing generation,year and model legacy hard to pinpoint anything further.

 

Ok thanks. Good information. Vehicle is a 2 litre twinscroll BP5

 

So a B13 model GTB ? which was built between 2003/01 (Revision A) and 2009/04 (Revision F)
All the info in post above applies although there was some slight changes for Revision D onwards (2006/02>)

 

Yes, is a GTB

 

2003