It looks like a big job but its not. You get at it from uunder the hood. Remove the plastic cover over where the heater hoses enter the fire wall. Its a bit of a pain but easy once the cover is off.
To reach the cabin air filter on a Hyundai Elantra the glovebox has to be removed. The filter is located behind the glovebox and can be easily replaced once the glove box is removed.
Funny I just did this to my 95 Firebird, Take out the glovebox and the stuff under it and you should be able to reach the Firewall from there, just drill your hole there.
Remove the glovebox and access the alarm module (3in square black box). Remove and ground #4 pin in harness plug to metal frame around the glovebox opening. Reach over and turn on ignition and restart previously unstartable engine.
(1) The water pump is failing and not circulating coolant through the heater coil. (2) the little "door" that opens the underdash ductwork isn't functioning properly - stuck in the closed position not allowing heat into the cabin. (3) Something is obstructing the heater hose or it is bent not allowing the flow of warm coolant from the engine block to reach the heater core.
The 2006 Toyota Corolla blower motor is located behind the glovebox. To reach it the glovebox and passenger side dash must be removed. The blower is located next to the evaporator. Remove the mount screws and disconnect the wire harness from the blower to remove it. Replace with new unit.
They can never reach that level of efficiency.
There is no heater control valve fitted on a Ford Escort. The heater matrix is directly connected to the engine's cooling system. To reach the heater matrix, you should remove all the facia unfortunately... :(
Low water in the radiator will result in no heat. The water level is not sufficient to reach the heater core. The heater core will become cold.
pull frame from around radio four screw located around radio open glovebox reach behind unplug power and radio ant pullout
reach up under the dash and unbolt the unit and take it out.
its hard you have to take the whole dash out to reach it i had a camaro and it was b****
There are two, they go from the engine to the firewall and Yes they can be hard to reach