Motorcar heating systems bear been encircling by reason of soon after Henry Ford introduced the Base T. Over the agedness, there hog been lousy with advances in the heating systems to encompass the clashing distribution methods to contradistinct levels of the sprint for higher quality passenger consolation. More useful authority over the constant of heat very as source of introduced air adds to passenger consolation. The air source can be changed to recirculated air or vented air from the atmosphere.
Types
The most basic heating system is manually operated completed the containment imagination. The switches comprehend:
1. The fan switch--this has four positions relative to fan precipitation
2. The temperature control--this, when turned, Testament either cumulation heat or cut heat
3. The position switch--this dictates where the air Testament escape from the sprint, either from the floor, sprint, or defroster and normally a position for a combination of any two positions. The vacuum is picked up from the engine intake manifold and transferred through a tube to the control head on the dash. The control head transfers the vacuum from the feeder tube to individual vacuum motors on the air conditioning and heating housing under the dash. These vacuum motors, when vacuum is applied, simply move an arm in or out to change the position of the doors. The doors work the same in all types of systems, the only thing that changes is the type of motors from vacuum to electric.
The desired position of the escaping air is further adjusted with a Press-stud. The process normally has a locate of vents between the front seat, and in some cases, above the headliner to alteration air to the rear seat position. When the door is unlocked, most units Testament burgeoning fan hurry to preserve temperature government and slow when it is closed.
Upgrades
Dual climate government is one of the newer innovations wherein the Chauffeur and passenger enjoy seperate controls for the akin and intensity of the heat discharge to their express seat position.
Many of the larger vehicles Testament proposition the possibility of dual air and heat where there is a completetly seperate heating development in the rear of the vehicle. The rear heat and air conditioning can be adjusted by the rear passengers in accordance to their needs.
Function
The heater's utility starts with the calescent drool. It is picked up from the vehicle's bathe pump and transfered over a hose to the inlet side of the heater core. The calescent imbue passes down the heater core and away the other side where the baptize is transfered back to the intake manifold or top of hose pump. The heater core is always boiling although the heat transfer to the interior of the vehivle is controlled by a series of doors within the heater core housing under the sprint. This housing contains the air conditioning evaporator very.
Door Control
The doors are controlled by the control head on the dash. The doors are operated by one of two methods. The first is by vacuum. The air escapes from the sprint one.The later type of heating course is the automatic climate direction. It utilizes two or else temperature sensors to accumulate the temperature fixed. To activate the development the automatic Press-stud is pushed and the desired temp is adjusted with an up or down Press-stud. The heater and air conditioning blower under the dash also remains the same except the complexity of the control panel. The speeds for the fan motor are controlled in all cases by a blower motor resister. In most cases this is located in immediate proximity to the blower motor. It controls the fan speed by supplying a varying resistance to ground.
Problems
If the fan does not work check the fuse first. If the fuse is good, pull the connector off of the blower motor under the right side of the dash and check the connector to it with a regular test light. With the key on, there should be power to the blower. If there is no power at the connector, put the connector back on and pull the connector on the heater blower motor resister and check for power. If it has power replace the blower motor resister and if it had no power replace the control head.
If the positions of the air discharge can not be changed to any position the control head needs to be replaced. If all but one position can be changed remove the glove compartment and look at the motors on the housing that is visible with the glove box removed. With the key on, move the control panel functions and watch each motor function by moving in or out. Check for a vacuum on the motor that does not move. Check with the engine running or in the case of an electric motor check for power. If either one has a source, be it vacuum or electrical than the motor is bad. If no source and a good fuse then the control panel is malfunctioning and needs to be replaced.
