I have a 2005 GTP and the heater will not blow hot air. The car has the dual zone controls and if I put it in manual mode and set both sides to 90 degrees it only blows slightly warm air. The coolant was a little low so I topped it off but no affect. Once the car warms up I notice that there are two hoses that go from the front of the engine and along the firewall. The top one is getting hot but not the bottom one.
Any input would be appreciated.