No heat in car

Hi Dave,

The only fuse are for the fans for the vents. If you have no heat coming from vents when you turn the heat to max, there is a problem with the internal heat exchanger (usually located behind the glove box on most cars). Vehicles use heat from the car's cooling system, i.e. the antifreeze from the radiator- to transfer to the passenger compartment. This is why you do not get immediate heat from the vents until your engine is warm. I hope this answers your question.

The heat shouldn't have anything to do with your car turning off and on. If there is a knocking while the heat is on then you probably have a heater motor going out in you.

LET YOUR CAR WARM UP FIRST!! or you risk the chance of over heating and casuing engine damage. start your car let it warm up for 5 to ten minutes and then try the heat. also when you start you should NEVER have heat on right away. the heat that you feel comes from the engine. and if the engine is cold and you are trying to heat it up it will put stress on the engine and over heat. ALL cars have to wait for their heat. that's why you see peoples car running in the morning with no one in it. so when they do get in it they have heat. heat will not work until the engine is warm.

Sounds like a possible water pump problem with the over heating part. About the heater only blowing cold you may have to get it "recharged"

Oh no! What do you do when your car heater not working? How do you figure out why there's no heat in car? What if you have no heater in car? Before you start trying to figure out how to fix car heater yourself, you should know a little about how your car's heating system operates. That will help you to figure out your car heater problem and why your heater isn't working properly or even at all! So, let's talk about how your heating system functions and then about some of the more obvious reasons that it you may be getting no heat from car heater. In order to heat up the inside of your car, the heating system uses some of the excess heat produced from your engine. Actually the engine produces so much heat that if you didn't have a way to release it (the heating/cooling system in your car) it could harm and even destroy the engine! That is why the heating/cooling system is set up to remove some of the heat and keep your car running smoothly.

Your car's heater is a life saver in cold weather. Before attempting to repair your car?s heater, you should understand how your car?s heater system works. First, on this page is an explanation of how your car?s heater system functions, further down the page are some pointers on heater system trouble-shooting. To warm the passenger cabin of your car, your car?s heating system makes use of excess heat from the engine?s internal combustion process. A car?s engine, in fact, when in operation produces so much excess heat that if the excess heat is not removed, it would destroy the engine. It is your car?s cooling system that removes that dangerous excess heat. Some of an engine?s excess heat is released through the exhaust. Most of an engine?s excess heat is absorbed by a circulating liquid coolant, which is a mix of water and antifreeze. The heated liquid coolant is carried from the engine through hoses to the radiator, which transfers the heat from the coolant to the outside air. That heat transfer lowers the temperature of the liquid coolant, which is then circulated back to the engine to absorb excess heat again. Whereas the radiator is located at your car?s front grill, the unit that transfers heat to the passenger cabin is located inside the dashboard. This unit is something of a mini-radiator and is referred to as the heater core. Heated liquid coolant circulates through tubes in the heater core and a heater fan blowing across those tubes, as well as through little fins encasing the tubes, directs warm air through heating vents into your car?s passenger cabin. Because your car?s heating system works off of its cooling system, heating system malfunctions are often caused by problems in the cooling system.

There are many many reasons for car heater not coming ON or not working properly:-- i will explain you the procedure to check this possibilities Your car's heater is a life saver in cold weather. Before attempting to repair your car’s heater, you should understand how your car’s heater system works. First, on this page is an explanation of how your car’s heater system functions, further down the page are some pointers on heater system trouble-shooting. To warm the passenger cabin of your car, your car’s heating system makes use of excess heat from the engine’s internal combustion process. A car’s engine, in fact, when in operation produces so much excess heat that if the excess heat is not removed, it would destroy the engine. It is your car’s cooling system that removes that dangerous excess heat. Some of an engine’s excess heat is released through the exhaust. Most of an engine’s excess heat is absorbed by a circulating liquid coolant, which is a mix of water and antifreeze.

The heated liquid coolant is carried from the engine through hoses to the radiator, which transfers the heat from the coolant to the outside air. That heat transfer lowers the temperature of the liquid coolant, which is then circulated back to the engine to absorb excess heat again. Whereas the radiator is located at your car’s front grill, the unit that transfers heat to the passenger cabin is located inside the dashboard. This unit is something of a mini-radiator and is referred to as the heater core. Heated liquid coolant circulates through tubes in the heater core and a heater fan blowing across those tubes, as well as through little fins encasing the tubes, directs warm air through heating vents into your car’s passenger cabin. Because your car’s heating system works off of its cooling system, heating system malfunctions are often caused by problems in the cooling system.
The heater core in your car is similar to the radiator in the front of your car; in fact it looks like a small radiator. The difference is the heater is mounted inside the car and air is blown through the fins of the core. The heater hosestransfer engine coolant from the engine to the heater core, this allows the heat from the engine coolant to be utilized and warm the passenger compartment. When a heater stops functioning determine what type of failure has occurred to execute a repair. We have listed the most common problems below.

please click on this link directly for more detailed help
http://www.2carpros.com/first_things/heater_failure.htm
check the diagrams and parts in the link to troubleshoot your care heater
This will help. Thanks please keep updated. please do rate the solution positively .thank you for using fixya

is the car over heating to the point the over heat light comes on and/or gauge pegs out max heat ?
if so u probly need a new water pump.
or is the a/c just warm air ?

have u checked thermostat could be stuck