New poster here with a question about my 97 Accord EX. I bought this car back in July of 2011 and did not do a full inspection of the heating and air systems, I took the seller's word for it that the systems were functioning. Rookie car buying mistake, live and learn. My car's defroster and heater do not work, both systems blow cold air. I changed my thermostat, my blower motor is fine, and I've tried different temperature control ***** as well as the control valve under the hood. The valve was stuck, I got it to open and close, however there is still no hot air. There are no bubbles in any hoses, and before I tear apart my entire dash to get to my heater core, I'd like to know if there are any little things that I could have bypassed that could be causing the lack of hot air. As far as I am aware, there is no binding present in the heater control valve cable. However, the actual temperature control **** turns all the way over to the right, past where to red coloring ends. Is it possible the rod could be broken, or something behind it? Any help is appreciated. Thanks.

 

Is the heater core control valve moving when temperature dial is rotated. If yes, turn to full warm and inspect heater hoses when engine has fully warmed. Both hoses should be hot indicating heated coolant is circulating through the heater core.

If one is warm and other cold, then very little or no fluid is getting through. It could be valve (only appears to open), blockage in heater core (remove heater hoses and attempt to reverse flush w/ garden hose), or blocked heater hose.

If both are hot, then the heat blend door is not opening (no air directed over heater core). Controls or damaged door. This is also controlled by temp control? not sure.

good luck

 

Thanks for the quick response. I checked to see if the valve was actually moving when the **** in the car was being turned, and it was not, it stayed in the same position while the **** was turning. So I would assume that my next step to see if the valve is broken or is binding? How would I diagnose that? Also, is there an easy way to get to the heater hoses?

 

Is the temp **** shaft turning? Check by removing the **** and turning the shaft with a pliers. Any action at the valve lever?

 

You can move the heater flow control valve by hand. It should move easily. If not the valve is frozen and may need replacement.

The push/pull wire may be disconnected from the heater control under the dash. If you move the heater temp select know, you should see the mechanism moving under the pax side center console region and nearby push/pull wire. As mentioned by Roader, make sure the **** is not broken and the stem consequently not turning. If valve actuation mechanism is disconnected from push/pull wire under dash you will need to reconnect mechanism to wire. You will have to figure this out yourself. I did years ago, but have forgotten details.

good luck

 

pull off the heater **** and see if the shaft is broken; if so get new one at Honda dealer

 

If this is the case, blend door adjustment is what you need....if you can't find it in a search, let me know.

 

I should have mentioned that I have taken off the ***** and manually turned the shaft with pliers with the dash off, the mechanism moves when the shaft is turned. I have also manually turned the control valve by hand, it opens and closes just fine. I spent a majority of the day looking for a blend door adjustment but have not had any luck in finding a help article. The **** itself does not look broken but I suppose there is always a chance something small is wrong with it.

 

I'm assuming that 97 doesn't have a motorized heat control like 98?? On my former 98 Accord, that cable only moves when the key is ON. Check to rule that out.

From the heater control there's a cable going down into the workings of the heater.


That first cable operates the air-blend door, and in the next picture I'm not really sure where that first cable attaches. Then there's a second cable (#10 below) from the heater unit going out to the water valve. Follow the cables & look for something disconnected or broken.

 

Suggest moving heat control to max and pushing the flow control all the way towards the firewall. See if this causes heat to flow from vents. This would confirm the air mix blend door is working.

Then you need to figure out how to connect the flow control valve push/pull wire to the under dash mechanism. Shop manual shows a loop in wire that fits over post on the heater control arm (under dash mechanism) and the cable sleeve is clamped to fix the sleeve.

Suggest downloading the 94-97 Accord manual from Online Manuals links in DIY forum this has the details described above.

good luck