How to Fix a Car with No Heat (Easy)

hey guys chrisfix here and with the colder weather around the corner today I'm gonna show you how to diagnose a problem where you don't get heat in your car truck before we begin anything turn your car or your truck to the run position and you just want to make sure that your temperature gauge here is low you do not want it to be in the middle or high because the first test we're gonna do is to check to make sure that we have enough antifreeze in the car and you can't check the antifreeze when the engines hot you get heat in your car because that radiator fluid that gets really hot runs through the engine through the piping into your cabin where there's like a mini radiator that mini radiator holds hot coolant it's called your heater core and then a fan blows over your heater core and that's how you get hot air and then when that coolant is cooled just a little bit because you have a fan blowing over it it gets sent back into the engine so if you don't have enough coolant your engine might be able to run at the correct operating temperature but because the heater core is so high up into the vehicle there might not be enough fluid to get into here and give you heat inside your car so the first step we're gonna do since the engines still cold we're gonna go check the radiator and see if there's enough fluid in here you just spin it counterclockwise and then when it won't spin any more you press downwards and spin it until it comes off Wow I'm definitely going to need to change this fluid very soon you can see it's all gunked up and that will bring me to another reason why you might not have heat but we'll get to that a couple seconds you can see the coolant is right up to the top here so this radiator is filled and now we'll put the cap back on and just twist this clockwise until it firmly snaps into place you wanna make sure that this is on correctly because this is a pressurized system your car might not have a radiator cap like this so just check your owners manual it'll tell you how to check your coolant that's just one of those basic things that every owner's manual has also you might have a coolant reservoir that you should check you could just go in here and see if there's any coolant and in my case there isn't any coolant so I'm going to add a little bit when you're adding coolant to this you want to go and look there's a cold fill line you can see it all the way down there it says cold fill that's where you gonna fill this up when the engine is cold so I'm going to add some coolant make sure you check your owner's manual to make sure you're adding the right type of coolant okay so now we know that our radiator is filled and we topped off our coolant reservoir now we can properly test the heating system and see if we have heat filling your radiator up with just a little bit of coolant like this might just be an easy fix for your no heat problem so now we're gonna go for a ride so that we could heat up our engine you want the temperature gauge here to be between the C and the H right in the middle and that's how you know your car is heated up and at that point you should have heat in your car so I'm just finishing up my drive you can see the engines at operating temperature and now that the engine is warmed up let me show you the other steps to diagnose a vehicle when you don't have heat so I've been driving around for a little while and that gauge has been pretty stable right there but if your car is overheating then the reason why you're not getting heat because the water pump isn't working typically a bad water pump will leak and the impeller will still spin but if it doesn't spin the hot coolant won't be forced into your heater core or even your radiator so your engine will overheat and you won't get any heat in the cabin you also might have a problem where your car never gets hot it doesn't get up to operating temperature and this could be due to the absence of a thermostat or your thermostat stuck open to find your thermostat all you have to do is follow that top radiator hose into your engine once you find your thermostat all it is is two bolts one there one there you unbolt those you take the old thermostat out put the new thermostat in and close it up so in this case since our temperature gauge is right in the middle we know that the thermostat and water pump are good just to let you guys know in my truck I actually have heat everything is fine I'm just going through steps for you so if you don't have heat or if you have a little heat you could diagnose the problem yourself so after the car is warmed up we're going to turn the heat on all the way and then we're gonna put the heat on the floor so my fan is working when it's on low it works when it's on medium and it works when it's on high if your fan only works when it's on high and you're not getting heat or a fan on the lower settings then your blower motor resistors probably bad and I have a video on how to replace that it's not a big deal it's a pretty cheap part and it's pretty quick and easy to replace now if your fan doesn't work at all you have it on all the different speeds and it's not working then your blower motors probably bed and I also have a video on how to replace that but if your fan does work and you're still not getting heat or it's not very hot there could be other problems let's say the air coming out isn't really hot like it's a little warm but it's not as hot as it should be what that typically is caused by is a quad heater core to check for a clogged heater core make sure you heat is on and we're going to go outside to the engine compartment when we look at our engine compartment what we want to do is we want to go back to the firewall typically on the passenger side or somewhere near the middle you're gonna find two hoses these two hoses go into the firewall and these are your heater core hoses so with these two heater core hoses what you want to do is you want to touch them you want to make sure that both of them are hot right now it's about 35 degrees on the blacktop so imagine how cold it is outside and then I'm gonna turn the laser on so you can see where I'm aiming I'm aiming right on the hose and it's about 140 degrees now I go to the other one same temperature 140 so both of these are the same temperature they're both warm they're hot to the touch make sure you don't burn yourself when you're doing this so I know my flow is good so if you have one that's hot and one that's cold the first thing you want to do is check the heater control valve which is this right here in my case my heater control valve is run by a vacuum in your case it might be electronic or mechanical either way all you have to do is turn the heat on and shut the heat off and see if this moves [Music] [Music] so if your valve is working it'll move in and out if your valve isn't working it won't move now if your heater control valve isn't working you're not gonna be able to get heat because it won't let coolant flow into your heater core and if that's the case you just need to replace one of these now if you just want to set this up real quick so that you have heat without fixing this all you have to do is take the vacuum line off and then clogged up the vacuum line here you don't have a vacuum leak now if it doesn't open up when you take the vacuum line off just manually open it up you can even tape it or rubberband it to something so that it stays open now that's just a temporary fix but it's something so you have heat if you have an electrical one of these you can unclip it from the wiring harness and test it to see if it's getting power when you turn the heat on if it's getting power your heater valve is bad if you're not getting power then there's a problem with the hvac under the - if your car has a mechanical heater control valve when you turn the dial for your heat you move a cable that opens the valve instead of using vacuum or electrical motor this cable can disconnect and many times you just need to pop it back into place to fix the problem and remember if you can't find a heater control valve your car might not use one so don't worry in my case this works fine so let's move on to the next thing to diagnose the other reason why one of your hoses will be hot and the other will be cool or slightly warm is because you have a clogged heater core you can attempt to reverse flush the heater core by taking off both of the hoses and running water through them to flush any gunk that's in there and might be clogging it up you could use a garden hose but make sure you use very low pressure because you could damage the heater core I have a video on flushing the heater core and the link to that video will be in the description now let's say both of your lines are cold and your heater control valve is working properly you might have air in the system since this is one of the highest points in your cooling system there's a good chance that air could get caught in here to fix that all you have to do is bleed your cooling system and sometimes with the heater on a few good revs of the engine will force that air out and that coolant in now one of the last things I'm going to go over to diagnose the heater system if you did all that and none of that worked well you could have a bad blend or actuator in some cars like this it's mechanical in other cars it could be moved with an electrical motor or using engine vacuum now what a blender does is it's a door that blocks either the air-conditioner or the heater so if you turn your temperature to the cool position right now the blend door will be blocking the heater core you don't want air from the heater core because you just want cold air now if you turn your heat on then the blend door will be blocking cold air coming from the car the blend door can also allow both hot and cold air to come in at the same time to get a desired temperature typically if you change your temperature quick like that you'll hear like a knock and that's the blend or just slamming shut I'm gonna change this quickly and we'll see if you could hear it so in mine you could hear the blend door opens and closes it's just that one click or one knock and it's functioning properly if you don't hear that on yours when you turn this quickly or if you hear a clicking so if I go from here to here and it's making like a deer stripping noise or like a plastic click like click click click click and then it stops that could be the blend or actuator which is up under the dash and it's connected to the blend or and it's just an electrical motor and the gears strip overtime and then your blend door won't move so it'll be stuck in either this position or it'll be stuck in that position either allowing cool air or hot air into your car so all you would have to do is replace that blend door actuator and that'll fix the problem or in this case since it's mechanically connected from the switch to the blend door you can look behind here for a connector that popped off and just reconnected the same goes for a blend door that works off of engine vacuum just look for a loose vacuum hose and reconnect it now these are the most common problems for no heat situations I hope this video helps you diagnose your problem as always you could comment below with any questions also remember to give the video a thumbs up and if you're not a subscriber what are you waiting for hit that subscribe button the top tip for this video is a basic maintenance tip on how to prevent a no heat situation because nobody wants to be left in the cold for their Drive the best way to prevent many no heat problems is with a coolant flush every few years and now if you're unsure if your coolant needs changing one way to test it is with the multimeter with the engine cooled down take the radiator cap off now start your engine and put the multimeter on 20 DC volts and take one of the leaves and put it in the coolant but only touch the coolant not the side or the metal of the radiator down below it and take another lead and put it on the ground if the reading is point three volts or more you probably need to change your cooling there are other methods to test your coolant and also I'll get more into this multimeter method in another video and the link to that video will be in the description below

Channel: ChrisFix

Views: 8,726,481

Keywords: how to fix car heater, broken car heater, car heater repair, car heat issues, how to restore heat in car, car wont heat up, no heat in car, car not blowing hot air, no heat in my car, how to tell if your heater core is clogged, no heat in truck, car heater not working, how to fix my car's heater, heater problems, no heater, how to bleed cooling system, how to flush coolant, how to change coolant, antifreeze, coolant flush, coolant change, coolant system, Honda

Id: -XjXTVJhFLM

Length: 10min 56sec (656 seconds)

Published: Sat Nov 22 2014