I recently purchased a 95 civic with some heat problems that I thought that I could fix. The symptoms were: cold air coming from vent even when engine is warm, no leak on the passenger side, new heater core, new thermostat, no overheating, inlet hose is hot prior to reaching the heater control valve but only slightly warm at the firewall, outlet hose is slightly warm. Could it be the heater control valve is not opening up and restricting heat flow? If that is the problem would my engine overheat?

I also managed to break off half of the bolt that holds the mounting plate for the heater control valve in place. Is it replaceable or is it soldered to the firewall?

Please help...

Martin

P.S.
Also, are the function control buttons on the temperature control assembly backlit. Mine arent and it just looks to me that they should be? in what state are they out of the factory?

 

maybe the cable for the control valve is faulty... have you tried to manually close the valve by hand???

 

yessir. i can move the cable both by hand and by moving the temp controls in the cabin.

 

it could also be a restricted heater core...... you can try bypassing the valve and hooking the hoses straight to the engine and removing the valve... the reason the valve shuts one way is to allow the max air funtion on the a/c....

 

Yes. Each control button has a small lamp inside it. They come this way from the factory. The two control levers (one for adjusting temperature; the other for fan speed) each has a back light, too.

Best bet is go to a junkyard, practice removing the climate control unit (a.k.a. heater control unit) and grab a bunch of these bulbs. The CCU is kinda tricky to remove. I practiced on a junkyard one then took careful notes the first time I took my 93's apart.

 

or double check all fuses bc if the bend door is stuck on the evap side than it wont put out any heat especially if the blend door actuator is electronically controlled.....

 

thanks kind peoples. i'll try it and let you know what happens.