VEHICLE: 2001 Jaguar S-Type Base 4.0L, V8, MFI, DOHC, VIN G
Customer Concern: There is no heat from either side of the heaters. Have already located the control valve and it has 2 solenoids. What is the voltage that the heater sends to those solenoids?
Tests: 1. The dual control valve has varying voltage input to it from the Air Conditioning Control Module (ACCM) depending on the temperature selected.
2. Check coolant flow through the heater control valve. The heater control valve should be located under the receiver/dryer on the front of the car and under the hood. The V-8 cars have an auxiliary electric water pump, which should also be running at idle when the heat is switched on.
3. The hot water valve defaults open, so when disconnected, all of the hoses going to it should be warm. If not the valve, it is plugged or stuck.
Potential Causes: Water Valve: Faulty/restricted hot water valve.
Air Conditioning Control Module (ACCM)
Coolant Pump: Electric coolant circulation pump inoperative.
Confirmed Fix: Replaced Dual Coolant Control Valve
Tech Tips: Connect/disconnect the hot water valve connector several times while tapping on it to see if it is stuck/plugged. Check for fault codes in the Heating, Ventilation and Air Conditioning (HVAC) system using a Jaguar WDS.