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.
Share a solution for this guide today!
Here are questions related to Troubleshooting Truck Heater Problems.
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.
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.
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?
Check your heater blend door motor.
I am having heating problems with my '99 Dodge Dakota.
By Manuel from NJ
Maybe you need a new heater core.
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
Check the fuses.
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
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).
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
By Mary (Guest Post)12/20/2008
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 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?
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.
The heater in my 2000 GMC Sierra on occasion will get warm, but doesn't stay that way for long. Will flushing my system work or could there be another problem?
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
The heat on my 2001 Dodge Dakota only works on the third setting half the time, but you have to giggle the key. All my fluids are fine, but I'm not sure what else it could be. Help?
I have a 1995 GMC K1500. My motor on the blower/fan was making a loud noise. I removed it cleaned it and oiled the shaft. I put it back in and it was still noisy. So I bought a new one and installed it. There are 5 screws and it only fits one way. Everything was good and tight.
I fired the truck up and turned the heat on high. It ran great for about 20 seconds then made a God awful noise. I took it apart and the fan was gone except for where it mounts to motor. My question is what caused this? And where did all the parts of the fan end up? Do I need to worry with them? I got Auto Zone to swap the part for free. I don't want to install till I know what's going on. Is there any way to vacuum out the passages to the vents? Please help.
By Stokes S
The air conditioner works, but heater does not. Any help?
My heater is not blowing on the floor or dash. It blows out the vents, but not warm air. The compressor keeps kicking on and off even when the A/C is not off.
I have a 2008 GMC and it only blows hot air. Please help.
By D.O. from Saskatoon, SK
The heater will not blow hot air. The truck doesn't run hot and cools fine.
Your heater fan is broken.
My heater knob was stuck and only blowing out hot air. Now it is stuck only blowing out cold air. The knob turns both directions.
My 2011 F150 blows hot air on the passenger side, but cold on the driver side.
I have a 2003 Dodge Ram 1500 and when I turn on the heater all I get is a little bit of heat only on low fan speed. When I turn up the fan speed it still blows, but cooler instead of hotter. Can anybody help me with my heater problem? Thank you.
By Daniel from Austin, TX
My 1999 Dodge Ram swaps from cold to hot and back randomly. What could be the problem?
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.
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. :(
I have only high speed on my Ford Ranger heater fan. How can I fix this?
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
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.
I asked my husband and he said the same thing as zoodad, so that is two in favor of so far.
I replaced the blower motor on my 2005 GMC Sierra truck. I also replaced the resister. The motor only blows once in a while on level 5 when I am driving. What could it be?
By Steve R.
My 1996 Ford Ranger heater will not blow hot air. Any suggestions?
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.
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.
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.
My daughter's truck heater won't stop working even when it is turned off. It is worse when the truck is accelerating, pressing on the gas pedal. We have tried putting it on the a/c side and it stills blows just as hot, and I mean really hot. My 1975 Dodge D100 has similar problems, while my Dodge Caravan just needs to be set to the a/c side to have it stop blowing hot at least. No one around our small town knows what we are talking about, meaning the mechanics.
By Laurie C.
My truck blows hot air when the fan is off and the temperature setting control is on cold.