2001 Jaguar XJR No Heat

The heater core could be clogged or you may have a bad blend door. To check, first make sure the engine is completely cooled down, the heater hoses can burn you severly. Look on the firewall on the passnger side of the vehicle. You should see two black hoses going through the sidewall. Put one hand on each hose (again, I emphasize, the engine must be cold to avoid injury) and have someone start the vehicle and turn on the heat. After about 2 minutes the hoses should be heating up. If both hoses are warm then its not the heater core. If only one hose is warm and the other is cold then the heater core is clogged or the valve is not opening. If it's warm on both sides, check for voltage to the blend door motor. You'll probably have to remove the glovebox or other dash parts to get to it. The door itslef might also be binding. If you've eliminated those possibilities then it might be the ac control head.