Hello everyone, new guy here. I picked up a 96 civic hatch a couple months back. The A/C worked great for the summer, but winter is arriving in Chicago and I needed the heat. Here is the issue. I only got cold air when I set the lever to hot. I looked under the dash and the cable was disconnected and there was no where to attach it (someone messed with the evap box previously and screwed it all up.) I tried moving the blend door manually both directions and never got heat. I also made sure the heater control valve under the hood was in the right position. Both hoses are hot going in and out of the firewall/bulkhead. I opened the box slightly right behind where the glove box sits and used a clothes hanger to pull the door in the other direction and then I had heat. Today on my way to work I was on the highway and engine had warmed up, but I was getting cold air. Got off the highway at a red light and low speeds and got cold then hot air. When I parked the car I checked again and was getting cold air only. This is really confusing me and Im not sure what direction to go in next. I appreciate any insight.

Thanks
Dan

 

Start by insuring there is no air in the coolant system, [bleed the coolant system].

Your car does not have a "blend door" it uses the water valve to control temp., the only "door" behind the glove box is the one above the blower motor, [recirculation door] #3, it is controlled by a motor #6... http://www.hondaautomotiveparts.com/...=HEATER+BLOWER
#7 Duct/Heater is replaced with #7 when you have A/C... http://www.hondaautomotiveparts.com/...G+UNIT+%281%29

The only other "doors" are mode control doors inside the heater unit #2 and controlled by the mode control motor #4.

The only cable should be the temp. control cable #6... http://www.hondaautomotiveparts.com/...ONTROL+%281%29 it attaches to the temp. control lever #4 and to the water valve #1... http://www.hondaautomotiveparts.com/...y5=WATER+VALVE

I need clarification on, "the box slightly right behind where the glove box sits" are you talking about the evaporator box?

Also what exactly do you mean, "someone messed with the evap box previously and screwed it all up" screwed it up how? 94

 

Ill take pics when I get home from work, makes it a lot easier. But the levers under the evaporator box have been messed with. they are not connected they way they should be. One is broken off. The other part of it, I removed the glove box. Then there was 3 bolts bolting a portion of the box on and 1 bolt connecting to the firewall. Then there were 3 c type clips i popped off and was able to yank that portion down enough to see inside (right at the A/C evaporator. I stuck a close hanger inside and pulled a door toward me and then started getting heat. Im not sure how the heater control valve is actuated with that cable but i had to do it manually.

 

This is a 96 Honda Civic, right?

Are there any dash modifications, [dash from another car]?

Does evap box look like the one I linked?

You said a cable was disconnected, was there no cable on the water vave, or was the cable disconnected at the heater control end? 94

 

Yes, 96 hatch DX. Dash is an original one. There is a cable going through the firewall to the heater valve. and another cable that was hanging under the dash the moves with the hot cold lever. I think I found the issue though. Im an idiot for not looking in the first place. Popped the radiator cap and was low on coolant. Thank you for all your insight fcm, I appreciate it.

 

Did you bleed the system after filling the rad?94