RepairPal is your advocate for car care advice and guidance

Q: heater on 1994 Mercury Grand Marquis

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
my heater doesnt work it wont heat at all
No car image 94a1663db56199c5353592009e34aaa51078a2469bed068bb8d6f0ba43accf97
Get a Repair Estimate
Guaranteed by certified locations nationwide. Learn more
RepairPal estimates are guaranteed at over 1,700 quality certified locations nationwide. Learn more
If your heater is not blowing cold, you can focus on two separate systems.

1) Is the engine itself getting up to the proper operating temperature? If the termperature is not hot enough, heat will not blow. Also, you could have a restriction in the heater core. Check the inlet and outlet hoses for how hot they get. They should both be very hot. Be careful of course when checking this.

2) You could have a temperature blend issue inside the car, which keeps the cold air from getting shut out of the ventilation system when calling for just heat. If the blend door motor does not work, it will not close the cold side and open the hot side (which happens at the same time on the same door). This motor failure is fairly common.

Look at your engine temperature first, then look on the inside. Good luck!
make sure the heater hoses are hooked up and getting hot both of them while the motor is running. If they are then its probably a blendoor not opening .
Didn't find what you were looking for?