I have a 1994 Honda Civic. I got it used recently (dirt cheap) and one problem with it is the heat. When I turn the heat on, it only blows cold air. The fan seems to be working because air is coming out but the air is cold. Needless to say I don't look forward to my morning drives to work now that we are in December. Does anyone have any idea what the problem could be and if it is a difficult / expensive fix?

 

Does your car oveheat? If so you might be low on coolant and that's why the heat won't blow hot. That's just one reason why it might not work. There are plenty others. That some else might chime in on later.

 

open your hood and look at the firewall by the battery there should be 2 hoses going into the car from the motor make sure they are not bypassed

 

Thanks guys. I opened the hood and the 2 hoses are there and seem to be fine.

I don't overheat and don't appear low on coolant.

 

Check the coolant level in the radiator itself, not just the plastic bottle. Never open the radiator cap unless the engine is completely cold. The radiator should be full to the very top when you take the cap off.

Does the engine temperature gauge on the dash come up to normal temperature-- about halfway up? If the engine never warms up you will get little or no heat.

If that's OK check that the lever on the water valve (mounted on the engine side of the firewall, one of the hoses passes through it) moves open and closed when you move the temperature lever on the dash from hot to cold.

 

I haven't been able to go out and check the coolant in the radiator itself yet (I am at work).

The temperature guage does go up about half way when I am driving.

One thing I forgot to mention is the 'fader' that you use to fade from heat to cool on the controls. It pulls towards cool. I got it to finally stick on the heat side though. Not sure if that helps? I originally thought that it was cold because that was stuck on the cool side and thought if I could get it to stay on the red/heat side, warm air would come out... I was wrong...

 

Probably is something to do with that temperature control lever then. It works this way: moving the lever activates a push-pull cable that goes to a mechanism on the bottom of the heater box (which you can see if you crawl into the drivers side and put your head near the gas pedal). This mechanism operates a rod that opens and closes the "air door" that lets air through the heater core, and also operates another push-pull cable that goes under the hood to the water valve.

 

make sure that t-stat is working properly not sticking open, also chk the heater cable adjustment, make sure that valve is opening and closing properly when you move from hot to cold

 

Thanks! Where do I check the heater cable adjustment? If that is the problem, is there any way to just stick it on hot for now?

 

Yes. In the back of the engine bay, to the left of the middle, you will find the heater valve. It is attached to two hoses and has a cable running to it. If you want to temporarily stick it on hot, push the lever on it to make the heater valve open (coolant flows through the valve and continues between both hoses).



In this pic it's directly behind and to the left of the container the hand in the picture is holding.