As did the author of this letter, you want your fan back. You can easily understand this issue. Rotated all the unmarked relays around in the junction box. To fix any blower, the first things to look at are the fuses, relays, and electrical connections. But as soon as they stop working, it's readily apparent. My radio, windshield wipers and ac/heater fan will not work. The ac/heat worked great until a couple days ago. Anyway, a blown fuse between an AC and your thermostat is kind of like a bad battery in your car. If the heater isn't blowing any air, skip to the next section. I work in the telephone business and am very familiar with DC wiring. Air conditioners and heaters accomplish their tasks unnoticed when working properly. However, attempting this without all of the info you need, destines your electrical troubleshooting process to failure. Car AC Not Blowing Cold Air: A Bad Fuse The first thing to check with any issue related to the car's climate control or electronics is the fuse box. The Front Blower Motor Relay (also known as the AC Relay), located behind the junction block with a black connector, B05, is the culprit. Turn the valve clockwise if the gas is off to allow flow to the system. https://www.lifewire.com/car-heater-suddenly-stopped-working-534657 Rotated all the PDC relays around, they have the same ID, other than ABS pump. Actually, you might have blown two fuses: the literal fuse connected to your thermostat and, if you're angry about your AC not working, an internal "fuse." So when I first start the truck AC/heat blows fine, but after about 10 to 15 minutes I am getting little to no air. I noticed the fan was not blowing any air through the vents. This is usually because the coolant has not been replaced in … One of the most common problems with an automotive climate control system is a lack of blower pressure or no blower at all. Why does my heater and ac work once in awhile? 7 Possible Causes, Troubleshooting a No Spark Problem in Honda Accord, Chevy Tahoe Expansion Block and Orifice Tube Locations. If the heater is broken because it's not blowing any air, it's likely due to a faulty blower motor or electrical connection. By using LiveAbout, you accept our, Check the Fuses, Relays, and Electrical Connections, Troubleshooting Common Condenser Fan Problems, What to Do When Your Car Won't Start or Turn Over, Troubleshooting and Fixing Turn Signal Issues, 9 Reasons Your High Beam Headlights Are Not Working, Why Isn’t My Car AC Blowing Cold? The only way to determine which component has failed is to grab some basic diagnostic tools, access the blower motor, and check whether or not it receives power. Check if the blower motor receives power. The Dodge owner's manual contradicts this and shows no 10 amp fuse for the purpose of a blower relay, inside the junction box. Turn the shutoff valve on a gas system counterclockwise; if the handle does not budge, the gas is turned off. If it receives power, check if the blower motor is burned out. All power to every one of the electrical working parts of the car is supplied via fuses. There is no battery to operate the blower. Fixing the motor should solve the problem in this case. https://www.thedrive.com/maintenance-repair/36766/car-heater-not-working If there was a short or a surge in the system, the fuse might blow to protect the delicate electronic components from damage -- but in so doing will render the system inoperable until the fuse is replaced. Heater control valve When you set the temperature to hot, air being passed over the heater matrix should be ducted into the cabin. Blower Fan is not working: If your car blower fan is inactive or damaged, car heater will work but warm air will not reach inside of your car. The Haynes manual says the blower is activated by a relay. If your car has no heat, not only would the inside of your car feel like an ice box, but a broken heater can prevent your defroster from blowing warm air to your windshield to eliminate ice and fog, which can pose a hazard while driving. To find out what's wrong with your car's heating system and what you can do to fix it, you first need a basic read of the situation. All of these are fairly easy to check. Reply 1: Can we get a little more detail about what happens when they are not working? It has A/C but is a short body and has no rear heat or A/C. The potential issues here vary whether your heating has gone out or your car’s AC system is on the fritz. But the narrow passages can become clogged. When winter arrives, the last thing you want breaking down is your car's heater because not only is a frosty car inconvenient—it's also dangerous. Is There a Cheaper Alternative to Air Conditioning? My problem is on a 1996 Dodge Caravan 3.3 liter. In a water-cooled car, the heater casing contains a matrix - a small radiator - that takes hot water from the engine through a hose. Of course, any central residential HVAC system is supposed to provide cool air when it’s warm outside and heat when the outside temperature drops. If the blower doesn't receive power, check the blower fuse to make sure it's not blown. You might be able to clear out your heater core passages by flushing them. Therefore, if major problems in the heating and air conditioning system fail, as if the power supply to the motor was completely cut off due to overheating or corrosion, the motor will simply not work, which in turn will render the entire heating and air conditioning system unusable, as no air will flow through the vehicle’s air vents. There is also an electric fan , which can be switched on to blow air through the system when the car is stationary, or when extra ventilation is called for. If the coolant level is low, the vehicle likely isn't circulating enough antifreeze through the heater core and needs to be replenished. Blower still does not work. By using Lifewire, you accept our, How to Fix It When Your Car Heater Isn't Working, How to Fix It If Your Car Heater Isn't Blowing Any Air, Universal Replacement Car Heaters That Work, Using a Space Heater as an Electric Car Heater. A leak from any of those places can prevent your heating system from working properly. If the vehicle burns coolant, it may have a blown head gasket, which can be costly to fix. The safest way to do this is with a non-contact infrared thermometer. Get the Latest Tech News Delivered Every Day, Lifewire uses cookies to provide you with a great user experience. If you can, try removing those controls and look for burnt or blackened wires. Follow these steps to fix the problem. Coolant travels through several parts of your engine. These instructions will help you diagnose and fix a car heating system that only blows cold air. This can happen when leaves, pine needles, or road debris are in the heating system. He also ghostwrites articles for numerous major trade publications. Then all of a sudden it started blowing full blast, while the recirc, ac, rear defrost button lights all came on and were flashing...then it all turned off.... - 1996-2000 Honda Civic If that doesn’t work, you’ll need to replace your heater core altogether. Filling the coolant may fix the problem in the short term. There’s no fan inside this heater which means that it’s a super silent option for your RV. Verify if this light turns on when you reach MAX A/C. Coolant that is a dark brown color indicates that there is rust in the cooling system. When you regulate the thermostat from hot to cold and don't hear the blend door moving, there may be a problem with the blend door, linkage, wiring, or the thermostat switch, depending on the vehicle. If your blower only works on the highest setting, your blower motor control module probably needs to be changed. If the vehicle has a valve in one of the hoses, check its operation. Not sure if it is a fuse problem or not. When this happens, your main concern is to get them running again as soon as possible. Your vehicle should have a complete relay diagram showing the location of all of the vehicle's electrical components such as fuses and relays. Air passing around the heater core is warmed by the hot engine coolant. Is the heater blowing cold air into the car, or is the car heater not blowing any air at all? Here are some reasons why a car’s heater may suddenly stop working. Checked for battery at the blower, when the car is running. Her expertise includes social media, web development, and graphic design. Top Reasons Central Heat doesn’t Work. Check out what he's been through, and why he should have asked an expert from the start. Check for debris in the heater box. Heater core internal passages. In the case of this Dodge's blower, the answer was fairly easy to discern. A blown fuse often indicates a different underlying problem, so never replace one with a larger fuse to prevent it from blowing out again. Blown Fuse or Loose Wiring. To do this, set the heater controls in the car to maximum heat, remove the radiator cap (or remote mounted coolant pressure cap, sometimes on the overflow tank) and fill to the correct level. Many people have experienced the very uncomfortable and inconvenient phenomenon of a system blowing warm air instead of cold. All the relays in the PDC have designated legends on the cover, but none indicate they are for the front blower relay. The freezing air makes you shiver, or the summer heat makes you sweat. This is often the case. Finding a Cheap Fix for a Broken Defroster, How to Fix Sweet, Mildewy, and Burning Smells From Your Car Heater, The 10 Best Portable Electric Car Heaters of 2021, What to Do When the Gauges in Your Car Aren't Working, How to Fix a Car Horn That Won't Stop Honking, If it receives power, check if the blower motor is burned out, If the blower doesn't receive power, check the blower fuse to make sure it's not blown. The coolant is housed in a translucent plastic jug in the engine compartment. An effective heating system can make for a much more enjoyable winter. It will however work when you turn the key all the way back or forward but not when the engine is running. Switch the thermostat from hot to cold and listen. If one hose is the same temperature as the coolant and the other hose is cold, there may be a blockage in the heater core. You Have a Leak. Can you help? https://twitter.com/mroffandonDIY: Fixing the Temperature Knob on an 1999 Hyundai Sonata. Incoming air goes through the water-heated matrix and is warmed. If cold air is coming out of the heating vents, even when the vehicle is warmed up and the thermostat is set to hot, you could be dealing with one of the following problems: If the heater is broken because it's not blowing any air, it's likely due to a faulty blower motor or electrical connection. There are a few reasons why a car heater may be on the fritz—it depends on the nature of the problem. If not, then we need to find out if there is a fuse/resistor issue with the fan, wiring issue, or the blower motor itself is not working. Dodge owners manual shows the 40 amp blower fuse, #25, but does not mention any blower relay in the PDC. I have a 2000 Honda civic ex. But a climate control system with no fan to push the air around is anything but controlled. You should see a valve near the furnace that controls the gas flow. The trouble relates to the blower motor and its activation. The heater core is like a miniature radiator built into the dashboard. Step 2: Verify that air is blowing. A motor failure will obviously may cause the fan failure, causing an overall car heater failure. There are many different places leaks can surface, so be sure to check your hoses, radiator and water pump for damage. You can adjust this heater from 3200 – 6000 BTU/hr and the catalytic heating is 99.98% efficient in comparison to flame heaters which are said to waste around 45% of heat produced and are not safe for use in a vehicle. If you replace a blown fuse with one of the same amperage and it doesn't go out, then the fuse likely failed due to age. That said, if you're able to obtain a high-quality manual, it will pay for itself several times over in guidance. Lift the hood and check the temperature around where the heater core hoses enter the heater core box. 2. The specific diagnostic procedure varies depending on the vehicle. https://www.wikihow.com/Diagnose-a-Non-Working-Air-Conditioning Fix this issue by your reliable mechanic. Note, there is no burnt or corroded wiring. Jeremy Laukkonen is tech writer and the creator of a popular blog and video game startup. Haynes also states this blower relay is powered via a fuse in the junction box from under the dash, #12, 10 amp. When a car heater doesn't work, the most common cause is low coolant. If the original fuse is not blown, trace the problem back to the source by testing the resistor, relay, and switch. 5. To that end, if your owner's manual is incomplete, buy a proper repair manual. I need to find the location of this front blower relay and the fuse that powers it. While there are a variety of reasons your Kia Optima heater is not working, the most common 3 are a broken heater blower motor, a problem with the thermostat, or a failed heater blower motor resistor. That means a trickle out of your vents instead of the rush you asked for. It sounds like the burning smell you noticed and the AC not working are related and since you noticed the smell in the cab of your truck it sounds like you may have a short in the wires in your ventilation control panel. If you determine that hot antifreeze flows through the heater core, there may be debris in the heater box. However, low coolant often indicates another problem, such as a leaking gasket or hose. You'll need to have it replaced before the machinery can do its thing. Blower still does not work. Turn off the vehicle and let the engine cool completely. Some reasons can be an easy fix while others may need the assistance of an auto repair shop in the Longmont area. Thermostat. Haynes say it is located in the PDC under the Hood, along with a 40 amp blower fuse in the PDC. Checked continuity of 40 amp blower fuse; it's okay. It should have level indicators that show how full or empty it is. If it does not turn on, it is an indication that either the switch itself is malfunctioning or the AC circuit is not getting power. But it sounds like the windows are down and you can hear the fan blowing but barely anything coming out. I just have to find the blower relay and its fuse. Check the heater core temperature. If the coolant is low, or there is an air lock (and also after replacing any faulty parts) you need to fill the system properly. If the valve is stuck and prevents coolant from flowing through the heater core, that may be the source of the problem. After removing the blower, you may find that the squirrel cage is clogged with so much debris that the motor can't operate. Such as blower fuse cut off or relay or damage of blower motor. LiveAbout uses cookies to provide you with a great user experience. If any of these three are leaking, your car heater won’t work properly. When it does happen, you're left with a miserably underpowered heat or AC system. Not having a working heater in your vehicle could even become a dire situation, if you end up stranded. Common reasons for the heating system not to work include the following: Low coolant; Air in the coolant system; Malfunctioning heater core; Failed (or failing) thermostat; The potential issues with the AC system are different, and include: There are many reasons why a car heater is not working. A blown fuse might just be the reason your car heater fan is not working. Christine Baker is a marketing consultant with experience working for a variety of clients. The way to do this is to go to the fan and test for power with the fan turned on. Matthew Wright has been a freelance writer and editor for over 10 years and an automotive repair professional for three decades specializing in European vintage vehicles. It is a 2003 and has 176,xxx miles on it. My blower motor does come on. There are some common reasons can occur this. Check the coolant level. If the air coming through isn’t hot, the heater core is probably clogged. In other cases, it may be a simple problem, such as a broken wire, rusted connections, or a disconnected pigtail assembly. There are many reasons why a car’s heater may not be working. The best repair manual is always a factory manual, but these can either be hard to find or many times more expensive than a "consumer friendly" repair manual. Verify if you are able to feel air blowing through the vents. The last common problem with car heaters is a water leak. If the fan isn’t working, you probably need to have the blower motor fixed or changed. It will still work with no fan, and you'll usually still be able to control the temperature of the air that is blowing or trickling, out.