AC - No HEAT onlly blowing Cold
11-09-2009
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AC - No HEAT onlly blowing Cold
Hi everyone,
I have a Honda civic 2003 si, and currently my AC blows no heat only cold air, actually cold/warm air, its almost that the temperature is set in the middle.
I drive one hour to work on the motorway/highway and still no HEAT, just Cold air.
The temperature is set at MAX (HOT/WARM).
Behind the console there is a wire that moves everytime you, switch between hot and cold, and thats not working properly as i need to manually push the wire to opens the HOT port.
But still no HEAT, after the HOT port is opened ... can someone please help me, I need the heat now more than ever, because its getting colder by the day with the winter here.
Thank You in advanced.
I have a Honda civic 2003 si, and currently my AC blows no heat only cold air, actually cold/warm air, its almost that the temperature is set in the middle.
I drive one hour to work on the motorway/highway and still no HEAT, just Cold air.
The temperature is set at MAX (HOT/WARM).
Behind the console there is a wire that moves everytime you, switch between hot and cold, and thats not working properly as i need to manually push the wire to opens the HOT port.
But still no HEAT, after the HOT port is opened ... can someone please help me, I need the heat now more than ever, because its getting colder by the day with the winter here.
Thank You in advanced.
11-09-2009
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Re: AC - No HEAT onlly blowing Cold
may just be a bad temperature switch. either that or clogged heater core. if you take out the glove box and feel around back there behind the dash, are any of the metal "pipes" hot?
11-11-2009
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Well, i got it sorted ... when switching from cold to hot .. the switch was bad (behind the console) ... it does NOT have enough strength to open the HOT PORT, so i had to manually push it to make the port open. But switching down to cold, works perfect, only when it comes to switching to HOT.
Thanks everyone
Thanks everyone
04-05-2011
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Im having the exact same issue. I just bought a 2002 civic si and not hot air blows whatsoever. I drive about 1 hour to work with the AC set to hot and nothing.. just cold air. What was the exact resolution this problem? and how do you open the Hot port manually.. Thank you in advance
04-05-2011
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start the engine and park the car. open hood, and look for the two smaller heater hoses near the back of the engine bay that are going inside the cabin. there should be a valve with a pin and cable attached to it. while you are looking at it, have someone else turn the temp dial to full cold, wait a few seconds, then turn to full hot. the cable should move the valve and open it so coolant can enter the cabin heater core and warm the air. if nothing moves, you may have a bad heater valve or a bad temp switch (the dial piece needs replacing). as a temp fix, i think you can turn the valve switch by hand in the engine bay. alot of times it gets corroded from salt and dirt and gets stuck in one position. its very common. i just looked at mine and while it still works, its badly rusted. you can try spraying it with silicone lube too as someone is turning the dial.
12-28-2014
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If you think a good mechanic is expensive, try hiring a bad one
01-01-2015
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i have a 2001 honda civic lx coupe. yesterday the blower was pushing cold air and the twmp gauge got just above normal. I shut down the heat and the temp went back to normal. today I started it and heat came out defrost and the fan wasnt working. how do I troubleshoot. fuse? why no heat when it was getting hot and then heat when car cooled down? Got a new headgasket and timming belt waterpump two yrs ago. has always use antifreeze about a cup every month. I know i have a small leak somewhere. They did a pressure test said it was ok. is it ok to drive 20 min on the highway today? 20 degrees out here? where is the fuse?
01-01-2015
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If you think a good mechanic is expensive, try hiring a bad one
Re: AC - No HEAT onlly blowing Cold
i have a 2001 honda civic lx coupe. yesterday the blower was pushing cold air and the twmp gauge got just above normal.
I shut down the heat and the temp went back to normal.
today I started it and heat came out defrost and the fan wasnt working.
how do I troubleshoot. fuse? why no heat when it was getting hot and then heat when car cooled down? Got a new headgasket and timming belt waterpump two yrs ago. has always use antifreeze about a cup every month. I know i have a small leak somewhere. They did a pressure test said it was ok. is it ok to drive 20 min on the highway today? 20 degrees out here? where is the fuse?
not sure if this is how to inquire about my issue but here I go. I have a 2001 lx coupe needed a headgasket and a waterpump. It has always used antifreese took it to get a pressure test said it was ok. Last month i filoled the resevior with antifreese and its so far down u can see the fill line on the resevior. so I wverfilled it. then i sat on the side of the road talking to a friend on the phone for a halfhour and the car overheated. I know I have a little leak. I see it a few drops ounder the car and i have to put about a cup in every month or so. now my fan isnt working as of yesterday. my car statrt to go just above the normal temp line and there was no heat..I shut the heater off and the engine temp went down. then I turned the heat back on and there was heat. I know its the fan also because this morning when I started it up the fan didnt come on like it usually does. could it be the temp gauge? please dont say headgasket again. I over heated before because i overfilled it that was probably a month ago no heat problems since then. How much is a fan or is it the fan belt that I should be saying and when I do that should I get a new themostat for go measure?
I shut down the heat and the temp went back to normal.
today I started it and heat came out defrost and the fan wasnt working.
how do I troubleshoot. fuse? why no heat when it was getting hot and then heat when car cooled down? Got a new headgasket and timming belt waterpump two yrs ago. has always use antifreeze about a cup every month. I know i have a small leak somewhere. They did a pressure test said it was ok. is it ok to drive 20 min on the highway today? 20 degrees out here? where is the fuse?
not sure if this is how to inquire about my issue but here I go. I have a 2001 lx coupe needed a headgasket and a waterpump. It has always used antifreese took it to get a pressure test said it was ok. Last month i filoled the resevior with antifreese and its so far down u can see the fill line on the resevior. so I wverfilled it. then i sat on the side of the road talking to a friend on the phone for a halfhour and the car overheated. I know I have a little leak. I see it a few drops ounder the car and i have to put about a cup in every month or so. now my fan isnt working as of yesterday. my car statrt to go just above the normal temp line and there was no heat..I shut the heater off and the engine temp went down. then I turned the heat back on and there was heat. I know its the fan also because this morning when I started it up the fan didnt come on like it usually does. could it be the temp gauge? please dont say headgasket again. I over heated before because i overfilled it that was probably a month ago no heat problems since then. How much is a fan or is it the fan belt that I should be saying and when I do that should I get a new themostat for go measure?
Multiple problems now.
Check fluid level in the radiator, not just the white plastic reservoir. The radiator is the most important part.
Fill radiator and burp air from the cooling system. This is probably explained somewhere in the other thread you posted in.
If the radiator is low on antifreeze, that could explain the overheat and lack of heater output (except for the fan problem).
You sitting on the side of the road for a half hour makes me wonder if the radiator fans have a problem running....or if the radiator is super low of antifreeze.
Overheating is bad bad bad!
No matter how new the head gasket is, an overheat event can cause it to breach and/or do more severe damage --such as warping the cylinder head.
Is the lack of heater output solely caused by the fan problem, or was it blowing cool air prior to the fan problem?
You had heat from the defrost, but no fan action? Was defrost not selected?
Fan inoperative: Which fan? The one for the heater/AC? Separate problem.
A little testing would reveal what the problem is......
I'll wild guess a bad power transistor for this, seems to be the most common failure.
If the radiator is found to be completely full and the radiator fans run correctly, then I might suspect a thermostat problem. But if coolant is real low then the thermostat probably didn't cause the problem. It could be damaged during an overheat event too, so watch out.
So....Seems like you should do:
Coolant level corrections and removing air from the system (burping)
evaluate radiator fan operation
diagnose heater fan operation
See if the other stuff works right or not
figure out where the lost coolant went, and why
12-11-2015
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I am a new member and this is my first forum ever. I have a similar issue with my daughters 03 Civic. Just had the radiator and heat core flushed and thermostat changed. All worked well for a few days. Now the heater temp stays cold for a bit then goes hot and fluctuated between with the temp **** on hot. Could this be a blend door issue? Any advise would be great. Keith
12-11-2015
#13
If you think a good mechanic is expensive, try hiring a bad one
Re: AC - No HEAT onlly blowing Cold
I am a new member and this is my first forum ever. I have a similar issue with my daughters 03 Civic. Just had the radiator and heat core flushed and thermostat changed. All worked well for a few days. Now the heater temp stays cold for a bit then goes hot and fluctuated between with the temp **** on hot. Could this be a blend door issue? Any advise would be great. Keith
12-11-2015
#14
If you think a good mechanic is expensive, try hiring a bad one
Re: AC - No HEAT onlly blowing Cold
Further....
Fan on full blast, heater will blow hot as long as the engine RPM is kept up. At idle the heater output cools off significantly.
Heater core has a big air bubble in it that is usually caused by low coolant level.
You may find the reservoir overfull or has overflowed....and at the same time the radiator is now at least a quart low.
This indicates the cap isn't sealing correctly, the system can't suck fluid out of the reservoir, or the head gasket is leaking.
Head gasket is all too common on that particular engine and very expected, and hard to diagnose correctly.
Fan on full blast, heater will blow hot as long as the engine RPM is kept up. At idle the heater output cools off significantly.
Heater core has a big air bubble in it that is usually caused by low coolant level.
You may find the reservoir overfull or has overflowed....and at the same time the radiator is now at least a quart low.
This indicates the cap isn't sealing correctly, the system can't suck fluid out of the reservoir, or the head gasket is leaking.
Head gasket is all too common on that particular engine and very expected, and hard to diagnose correctly.
12-11-2015
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Exonerated, thanks for the quick reply. Was wondering why you think head gasket. I was thinking blender issue. It doesn't use any antifreeze. I welcome your thoughts.
Keith
Keith
12-11-2015
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If you think a good mechanic is expensive, try hiring a bad one
Re: AC - No HEAT onlly blowing Cold
I was thinking blender issue.
You can note the position of the lever on the valve while heat is working, then determine if the valve (and therefore door) has moved when you feel cold.
Was wondering why you think head gasket.
How low is the fluid in the radiator?
12-12-2015
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Turns out the antifreeze was low. Just had heat core flushed. Must have had an air bubble in the system. Added about a quart and all is good. Thanks for the ideas.
12-12-2015
#18
If you think a good mechanic is expensive, try hiring a bad one
Re: AC - No HEAT onlly blowing Cold
Keep an eye on the radiator level, check every few days for a while to make sure it isn't disappearing .
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