When your vehicle's heater is not blowing hot air, you need to figure out why not. This guide is about troubleshooting truck heater problems.
By rloredo 1
I have a 2004 Silverado. The heater works on one side, but not the other. One side blows hot air, but the driver's side doesn't, it blows cold air.
By Will 1
I am stumped. I can't seem to get anything more than lukewarm air out of my heater. I have flushed the radiator, put in a new 190 degree thermostat, a new heater core, new hoses to the heater, cleaned the heater housing, and made sure all the controls are working and flaps are moving. The water pump is good. The hoses get hot, and there is a new fan.
My 94 Ranger has a heater problem that I can not figure out. First off the the temp gauge does the windshield wiper thing, up and down, up and down. To make matters worse, often there is no heat. I have changed the thermostat and that didn't help. The top hose from the radiator does get warm, sometimes the heater hose gets hot. I've flushed the system once already. Any ideas?
Richard from Waterford, CT
December 1, 2008
Sounds remotely like a possible plugged heater core, to flush take both heater hoses off and flush with a garden hose.
By guest (Guest Post) Flag
December 1, 2008
You could check for a broken head gasket. Check the oil on the dip stick and see if there is any water mixing with the oil. Or take it to your mechanic and he will check the oil.
By guest (Guest Post) Flag
December 20, 2008
My husband had the same problem with our 93 Ranger. Several years ago, after driving for 2 Chicago winters with no heat (he tried all the usual stuff), I suggested he SOAK the heater core in CLR over night. Then he flushed it SEVERAL times with clear water, reinstalled it and it still works fine! He is toasty warm...of course NOW the Air Conditioner does not work...but his window does!
I have an 04 Chevy Silverado 5.3 and I'm having heater problems. I'm not getting any air hot or cold blowing out, but when I get on the highway a very small amount will blow out. Days will go by and then out of nowhere the blower well start to work and blow perfectly fine on all speeds for a day or so and then it will stop.
By Andrew S. from Kansas
February 7, 2014
This same thing was happening in my husband's jeep. It was the heater core that had to be replaced.
February 10, 2014
Try having this done. Back flush the heater core. It cost me $100.00 to have. I had no heat at all.
I am 79, coming on 80 years old and still learning about a car. I own a
1994 Ford Crown Vic named Louie and he takes me everywhere. Hope this helps! Mrs C.
My 2006 Ford Ranger is blowing hot air all the time. The cold to hot knob seems not to be working. If I put it on outside air it blows hot, if I try to use the a/c it's hot. I live in Dallas, Texas and it's hot and I need to use the a/c, but I can't. How do I fix this issue?
July 21, 2015
Most likely you need to take it to the shop and have them put freon gas in the air conditioner. As they age, air conditioners leak the gas bit by bit and when it's gone they won't cool any more. It's not something you can fix yourself. Good luck!
I have a 1998 Ford Explorer. My heat went out a month ago, but just by dumb luck I started hammering around the metal housing, and luckily, the heat came on. But now, the tapping doesn't work anymore. I use to get some warm air, but now I have none. Is it possible that my blower motor went out, or could it be something else?
By Tiffany S. from Gary
February 7, 2014
More then likely it is indeed your blower motor that has died.
How do you get to the heat and ac vents that distrbute hot and cold air to the windshield? The hot air and cold air won't blow out of the bottom or windshield vents.
By Dixie M. 1
I have a 1994 Ford 150 truck. The heater barely gets warm air into the truck. I have had the heater core and radiator flushed. What else should we do?
By Dixie M.
November 15, 2014
Get a repair manual and do it yourself. Mechanics charge to much and half the time thay are guessing what the problem is so you pay for parts you didn't need.
How do I fix my 2008 Dodge Ram1500 heater? When I adjust my heater to the floor it goes to the defrosters.
By Joel from Warren, MI
The heater will not blow hot air. The truck doesn't run hot and cools fine.
I have a 1996 Ford Ranger. Recently the heat stopped working. I changed the thermostat and the heater core and still no heat, please help.
February 7, 2013
We bought my daughter a 1998 ford ranger. The air conditioner would not hold charge. Then the heater would blow luke warm air even after running for a long while. Since I really dont know if yours is doing this or just not working all together. It's really hard to say but, here is what we did to fix hers with her problem. It's called air door actuator.
If you are close to a napa store the part number is 655-1551 (this was for a 1998), but still might be the same. And here was the kicker; t was located inside of the glove box. Well the glove box was taken out it was in behind it. Hope this helps or it may help someone....and my husband says I shouldnt keep all those boxes of used parts...lol.
I have checked the thermostat and the flaps. The heater hoses are hot and still the heater does not heat the cab. What could be wrong?
By Dickie G.
December 8, 2011
More than likely it's the heater core, mine is in the same fix. I have a Ford Ranger XLT and mine went out a couple years ago. My husband bought the core and was told the whole dashboard has to come out! He thought it came out from under the dash, but no, it didn't, what a job to do. I drove my car and he drove his truck and that's why it hasn't been fixed yet. :(
My 1996 Ford Ranger heater will not blow hot air. Any suggestions?
November 5, 2011
I would check the thermostat. You should always replace the thermostat when changing the coolant with a high temperature thermostat. Sometimes people have the coolant changed and replace the thermostat with a low temperature unit and that will blow cooler air. My car was blowing cooler air but the reason was my coolant was down little over a half a gallon.
My truck is a 96 S10 2.2l with a manual transmission. The heater is not functioning. I have flushed and back flushed the heater core already and changed the coolant and flushed it too. So now I don't know what to do. I need help guys.
By Jon P.
October 31, 2011
I asked my husband and he said the same thing as zoodad, so that is two in favor of so far.
How do I fix a 2007 Ford Ranger heater? It has been to the shop and they said there was no problem with the heater core, but only a leak. It still does not work.
March 6, 2013
Turn your cold to hot mixture knob back and forth and listen for it to open and/or close. Mine puts out either cold or luke warm air. I was pulling a uhaul trailer and the temp never went above low on the guage. When I stopped because I thought I was low on coolant I was able to actually remove the cap and see it was full also put my finger in coolant and it's luke warm. I've changed out the door on a ford RV that one wouldn't move so you wouldn't hear it close. I flushed my system and I will be replacing the thermostat.
Please help, it's getting cold. The heater is not working in my 1999 Ford Ranger. The heater core is getting hot and air is coming through the vents. I can't locate the transfer door between the heater core and the evaporator core. Where is the actuator? Is it vacuum or electric?
By Mike from Millington, TN
April 5, 2011
Go to Auto Zone and they will pull up a print out for you and you will find it. The most likely cause is a vacuum door is not opening cause by a broken or loose vacuum hose, listen for a hissing sound and you will find it, it will be under the dash near the big black box (heater box).
Something fell in. How do I get it out?
Why does my heater not blow hot air when it is turned to the red on the switch?
By J W
My truck heater blows hard, but does not get hot. If I turn the mix down it gets cool, but if I turn the mix up to total hot it gets lukewarm. There is a new thermostat, new hoses, and new fluid. It just don't get good and hot. The scan shows 180' hoses in and out of the heater core are hot going in an cool coming out. Could it be blocked in the cold hot mix? Can someone help?
The blower blows hot and cold, but won't defrost and the windows fog up.
My 2009 Ford F150 4x4 is blowing only cold air with the heater on. Any suggestions on what the problem could be?
Why do my windows fog up when I put the defrost on in my Ford pick up and it blows warm air?
By David E.
My 99 S10 v6 heater/ac blower works well except the fan doesn't blow air/heat on the floor setting or the combination floor/vents. When I put the selector on floor setting, I can hear the "door" directing it to the floor open/close, and the fan running, but nothing is coming out of the floor vents. Also the blower doesn't work on the #1 setting no matter what vent setting. Position 2 - 4 works on all except the floor.
By Jerry c
I have a 1998 Chevy Z71 1500. My heater won't blow hot air unless I am driving it or giving it more throttle.
December 27, 2014
After reading several of your "why don't you just take it to a mechanic?" posts I feel compelled to respond. The whole idea behind these sites is to give people with some mechanical aptitude a chance to get advice on their car troubles so they, in turn, might be able to fix them. Labor is generally the most costly part of a bill from a mechanic and in some cases, worth it to have a professional do the work. However, there are many instances in which simple car problems can be handled by someone with some mechanical abilities and a few tools saving potentially hundreds of dollars on a repair bill. I hope this helps you understand the premise behind these sites.
I have a 2009 Dodge Ram truck. When I turn the heat, air, or defrost on it is not working. Nothing is coming on.
December 22, 2014
I have a 1998 Ford Ranger Truck that the Heater Module Switch went bad. A/C works fine but it doesn't do much good as a defroster. The 12 volt Defroster that are sold are about 12 Watts and don't do anything, don't waste your money.
What I did was buy a 400/800 Peak Watt Inverter, an extension cord and a 200 Watt Lashko Heater, total cost $60. I place the heater on the dash on a rubber mat so it doesn't slide and turn on the heat and use the blower on low to distribute the heat. It dried up the moisture and defrosted my windshield just fine. My girl friend placed it on the floor boards and heated up the cab in no time. It was made to handle a office cubicle so a truck cab is no problem. There is no tip over switch on the heater so care must be used. It's only 200 Watts and the Inverter handled it with no problem. When I shut down, I shut off the Inverter so it doesn't drain my battery. Only problem it scrambles the AM radio signals but not FM, I can live with that when its C-O-L-D.
By David L. 1
My Chevy S-10 pickup heater only works when I drive fast. It'll work for a few seconds and then stop blowing hot air.
By David L.
I have a 99 Dodge 1500 that the heat blower works fine until you turn the head lights on; then there is no blower. Tried all settings and it just doesn't blow. If you turn the headlights off the blower turns on.
By Jamie G.
January 14, 2015
Louise, we all understand you are proud of your son, and I am sure he is a great mechanic...but replying to every post with "find a trusted, reliable mechanic" isn't really what this forum is about. This is for those who are mechanically inclined and may be able to fix the problem themselves.
I have a 2005 Chevy Colorado; it will blow heat and a/c and then it quits after awhile. If I shut the blower off for a little bit it will work again. I don't know what's causing it.
October 2, 2014
I'm not sure, but I too have a 2005 Chevy Colorado, and my blower only works on high. I'm wondering if this is a problem with Colorado's? I've checked for recalls, but have found nothing on this. Hopefully someone else will know the answer to your question... :)
I have no heat in my truck. I have flushed the heater core and still no heat. I did change my thermostat and both hoses are hot going in and out of the core, but it is not blowing heat in the truck.
December 16, 2014
I've got a 2000 f150 with the same issue. I am flushing the heater core this weekend as I believe I have a partially clogged core, also I'm doing the air blend door actuator, sounds like the air blend door actuator may be your issue. It's a $30 part you may pull yours off and check that. It's located behind that black panel, down where your air for your feet comes from, its black and white if you need I can send you a pic, let me know if thats your issue, and if you've already found your issue please let me know what it was so I have an idea on my truck. Thanks in advance.
By LC Waller 1
I have a 2000 Ford Explorer V6 4.0L SOHC. I was changing the spark plugs and saw two bad collapsed hoses, so I changed them. Afterwards I noticed my heat did not work, but it still blows harder than before. What could it be?
By LC Waller
Why does the fan in my '98 Chevy 1500 turn on and off by itself?
What would be the problem if there's no power to the plug for the resistor?
By Samuel from Russellville, AR
February 17, 2014
The guide that is attached to this post has a lot of good suggestions. Here is a direct link to that guide. Click on any post to see all the information posted.
If you find a solution, please report back and let us know what you found.
My 2006 Dodge Dakota heater/conditioner makes a fast clicking sound when I change from floor to defrost, etc.
My heater only blows hot air on the low setting, but cold air on high.
January 17, 2014
This usually means the antifreeze is old, and needs to be changed. It still has some ability to hold heat, so you get heat on low, but when you switch to high the extraction of heat is faster than the fluid can absorb. Replacing the antifreeze solution completely should solve this problem. You might also want to look at your thermostat, since a poorly functioning thermostat can create the same problem, except it never allows the heat to build up as high as it once did.
I have Ford E 250. The heater blower works, but there is no hot air.
January 17, 2014
Is the thermostat working? A poorly functioning thermostat never lets enough heat accumulate.
Does the antifreeze test in the correct range? Old antifreeze can't pick up heat fast enough to deliver it to you. If you get warm air on low, and cold otherwise the antifreeze is prob the first thing to check.
The heater core can be at fault. The hoses to and from the heater core. Check or replace them. A leak anywhere in the system can cause these problems.
Ford usually has excellent heaters, but they can only work well if everything is in good shape.
The blower on my '91 Explorer was only working a little bit. It had all the signs of the resistor going bad, so I replaced the resistor. Now the blower works at the lower speeds, but not at the high speed. What might the problems be?
January 14, 2014
I'm pretty sure it's the wiring harness. I had a Chevrolet Colorado with the exact issue and it was the wiring harness. If possible you could take to a garage that specializes in electrical issues and have the work done much, much cheaper than dealer. Hope this helps.
My new pick-up is blowing hot air out of the vents even when my heat is off. The only way to stop this, is to close all the vents and that's hard to do when driving and the other vents are on the other side of the truck. Once the heat is off I should not be getting heat coming out of the vents. This is over heating the inside of the cab and I have to open windows.
Does anyone know why this is happening? They have a recall that a part will cause a fire. I wonder if this could be happening to my truck? I am going to take it in once they send the letter for recall. Thank you!
Sometimes it does, but not all of the time. It is just warm, not hot.
By James R. 1
I have a 1992 Chevy s10. The heater will not blow hot air and the only air that it does blow comes out of the floor vent behind the stick shift. It comes from there no matter which setting it is on. Any help would be much appreciated. The cold has set in.
By James R.
December 27, 2013
If you're air is just barely blowing, you may need a new blower motor. If your air is blowing, but isn't hot I would guess that you need a coolant flush. Hopefully you don't need a new heater core. But I digress. . .
If you can't change the direction of the air flow in your pick-up chances are that the cable or control arm connected to the actuator broke. Could be that it somehow disconnected, but not likely.
If you're feeling frisky you can go to your local library and review a Chilton's manual or something of the like. If I remember correctly, you'll want to locate a GM pick-up manual. You'll find step-by-step instructions on how to take everything apart.
Remember: It's not that working on your vehicle is difficult. It's just a matter of how much time it takes, and whether or not you have the tools to do the job. To my experience you'll most likely need some screwdrivers, a socket wrench with metric sockets, and some star bits. And a good light source is a must. You can get a "security set" of something like 100 bits at Harbor Freight for about ten bucks.
Take your time, pay attention, and make the effort to be organized.
I recently changed out my heater core because it was leaking. I purchased an after market part which turned out to be slightly smaller than the original. After putting everything back together I didn't get the same heat as before. If I sit parked I get heat, but once I drive down the road, it cools off. Someone told me if I put it on max ac, it will recirculate the cab air, and then it works decently. If I switch it to defrost or any other setting, it starts to cool down. It's as if I have too much air coming in and bypassing the core. The gauge on the dash says the temp is good and I have done everything possible to trouble shoot this (thermostat, bleed the coolant line, etc.). I also have a draft coming from the passenger side under the dash. What am I missing? I had plenty of heat before this all took place.
By Kent R
February 1, 2014
I have a 1995 Chevy Silverado k1500 and I have the same problem. If you have fixed yours please post the issue. I also have had my hand on the heater core when hot then turned on the fan to blow hot air and half the core will be ice cold while the other side of core is hot. This is with the brand new core put in.
My heater only blows air on the highest setting. No air comes out on low or mid settings. My blower motor went out and I replaced it, but now it only blows on high. I have a 2006 Ram 1500 truck.
By c. gamel
I have cleaned my system out. I have made sure my hoses were not crossed, I have coolant, I have changed my thermostat and I have also made sure my core was not stopped up. I still have no heat, just cold air. I have checked my flap with my knob controls and it opens and closes. What can I do for the problem?
October 30, 2013
Don't worry about the air duct flap. Find the fluid control valve, that sends hot radiator fluid to the small interior radiator. Most likely that valve is stuck.
On most vehicles that valve is a rotary type valve, and luckily, some WD40 and some energetic cranking back and forth with some vise-grips for a few minutes, will loosen it up. Disconnect the wire or cable pull running to it, before you start forcing it.
If you can't loosen it up, replace it.
My 2001 Ford 150xl v6 heater was making a flapping sound for awhile and has stopped. It stopped blowing heat, but would work by tapping the heater now there is no heat. What is the problem?
I have only high speed on my Ford Ranger heater fan. How can I fix this?
January 6, 2012
Hi, my car did the same thing. It is the heat resistor fan speed control switch. t is usually found near the firewall on the passenger side. The part can be bought at most any auto parts place, cost about $35.Google your vehicle/heat resistor fan speed control switch and you should be taken to a page showing you where it is located. Good luck, Kathy
By manuel 1
I am having heating problems with my '99 Dodge Dakota.
By Manuel from NJ
The a/c is not blowing cold in my 2004 Ford Ranger.
By Dennis from Rockledge, FL
I have a 1997 Dodge Dakota extended cab, 5 speed. The heater and air conditioning unit isn't blowing cool or warm air into the cab. It doesn't seem like the blower is working. Any advice on fixing it would be appreciated.
By George from Franklin, PA
I have a Dodge Dakota truck 2006 and it will not blow out heat.
I have a 2001 Chevy Silverado. The AC works fine, but when I turn on the heat it blows only lukewarm air at best. If the truck is hot it will come out warm for a minute when I first turn it on, but it does not last. It is hot when the blower is off. I have not checked anything as of yet. I was told the actuator may be stuck. Is there a way to determine if it is the heater core or the actuator? Any tips would be greatly appreciated.
By Isabel M. 2
My father's truck has an AC that won't turn on and a heater that won't turn off. I was thinking it could be the blend motor, but I'm only 14 so I need some help. I am fixing it for his Father's Day gift. Any advice helps.
I have a 2008 Dodge 3/4 ton truck. Why does my heater blow out of the dash, but not out of the defrost or floor vent?
When the heater is on and the truck is completely warmed up it just blows cold air. The temperature gauge starts getting hot and when I quickly accelerate the temp drops and the heater starts blowing warm hot air. It does good for a while, but then will go back to blowing cold air when I start slowing down and the temp gauge goes back up. If I repeat the quick accelerating it drops in temperature and starts blowing warm air again. Any clue as to what this could be? Please help!