My heat blows out of the passenger vents but blows cold air out of driver vent…what is the issue???
My car has 42000 miles.
My car has an automatic transmission.
How to Identify and Fix Common car Problems ?
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A faulty or broken thermostat is the most common cause of your car`s failing heat. Stuck open or stuck closed, the part can not only cause issues with your heat but also with your engine`s cooling system. One becomes an issue of comfort, the other becomes an issue of “Oh no, I`ve borked my engine.”
Relevant Questions and Answers :
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Climate controlled vehicles have multiple electrical relays that open and close vents to maintain the desired temperature. In some instances, these relays can wear out overtime. However, it’s also common for debris to clog up vents (especially side vents) which may restrict the flow of cool air. The best way to determine why your AC is not working efficiently, it might be best to have a professional mechanic complete a AC inspection; so they can pinpoint the source of your issues and recommend the right repairs.
If your engine is not overheating and you’ve flushed the core and coolant correctly, it’s possible that you may have an electrical issue causing the heater to not function correctly. I’d start by checking fuses and relays powering the heater core first before you begin to remove components. If the issue does not clear up after checking electrical, there may be a problem with your heater controls. You might want to purchase a service manual for your 2003 GMC to get specific locations of all control vents before you remove the dash; as it’s very complex under there and can be difficult to repair and replace. If you’d like to have a professional mobile mechanic assist you, contact our team and set up a heater is not working inspection.
Engine overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, all the time or sometimes not at all. When this happens you will notice a temperature spike and drop occasionally as the fan comes on and off. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. As mentioned above, this also restricts the warm coolant from flowing through the heater core which uses this to blow warm air into the cab of the vehicle. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.