heater blows cold..
 

I turn the heat on in my car and get no warm air even after a long drive, no heat. The fan blows, just lots of cold air. All fuses appear to be fine........ any ideas?

RE: heater blows cold..
 

make sure your collent is full..thats always the number one problem.

RE: heater blows cold..
 

should be full but ill check in the morning...

RE: heater blows cold..
 

If your coolant level is okay, then check these other possibilities for a 1996-1998 Civic (see picture).

The 1999-2000 Civic, on the other hand, has a self-diagnosis function (see picture in next post).

[IMG]local://upfiles/25538/D624777046D544DEB591D23FBD4F5780.jpg[/IMG]

RE: heater blows cold..
 

Last picture...

[IMG]local://upfiles/25538/858327CFC90F4EE29824FF77BB55494B.jpg[/IMG]

RE: heater blows cold..
 

Most common cause of this problem (after low coolant level as already mentioned) is a bad thermostat so the engine never warms up. The temperature gauge on the dash will stay at cold.

RE: heater blows cold..
 

No the engine temp comes up to normal, but i still never get any warm air to blow into the car. Its cold in the winter i need to get this working lol. Ill check out the stuff you guys mentioned thanks.

RE: heater blows cold..
 

The picture shows the troubleshooting chart for a 1993 Civic.

[IMG]local://upfiles/25538/2CE2D34AA9C94FED9EDB568407A90898.jpg[/IMG]

RE: heater blows cold..
 

Probably bad thermostat. It's not letting any hot coolant into the heater core.

RE: heater blows cold..
 

The thermostat controls flow thru the radiator only. Hot water from the engine can always flow to the heater core. But there is a valve controlled by the temperature lever on the dash. When it is on cold the valve closes, on hot it is open.

So I'd check the valve next. It's mounted on the firewall under the hood with a heater hose leading in and out of it and a mechanical cable that is ultimately controlled by the lever on the dash. Make sure it moves when you move the lever.

If the valve seems OK then warm up the engine and set the heater on hot and feel both of the heater hoses to the firewall. They should both be hot. If only one is hot then there is likely a blockage in the valve or heater core. Sometimes that can be flushed out by draining the system disconnecting the hoses and flushing water thru the core with a garden hose.

If both hoses are hot then the air control door inside the car must be the problem as it is diverting the air around the heater core. That is supposed to happen with the control on cold but when you set it to hot the door moves and air goes thru the heater core.