A/C-Heat

[bobob]

My a/c - heater blows only cold air at all times ( vent,defrost,a/c,heater,mix ). I rotate the temperature dial to hot but still get cold air. Any ideas ?

 

[wileec]

could be that the temp dial is disconected? I think that it is a electricly activated gate at the heater core now. Would need to trace the conections but am not sure how that system is activated.

 

[Seabronc]

When the fan is on, does the air only come out the defroster vents? If so, check the vacuum source line which comes into the dash on the right side of the fire wall.

Good luck,

>-

 

[2NDTOUR89]

Check your vacuum going to the mode door actuators. If you have no vacuum to them or the actuator is bad, it will not open the door to the heater box...

 

[Big Ragu]

Hi Dont want to sound dumb or anything like that........but.... did you just get this truck? have you ever use the heat? I'm only saying this because I live in central Fl. transplanted from N.Y. been here for 6 years, bought my Bronco here. Only once in the 6 years of being here did I need the heat. Last Jan. had my son in the truck and we were out wheeling. He's a little guy only 7 and he was a little cold so I put the heat on........nothing but cold air. No matter where I put the dials.......cold air. So when we got back home I started looking for the problem. And thats when I notice that the heater core was by-passed!!!!!!. 5 1/2 years of owning this truck and finally finding out that the heater core was by-passed !. I spent the next 2 hours going over the rest of the truck to see what else it has and dont have and found out that I have little pop out cup holders and ash trays in the back!!! and a jack that is useless on my truck. Now I have a high lift jack, new heater core which by the way took no time to swap out....Oh yea... and pop out cup holders and ash trays that still dont get used.

Ragu

 

[EvlFaust]

I would have to agree with Ragu, take a quick look to make sure that your heater hoses are not connected bypassing the core. I live in Las Vegas and I see this type of thing quite often in many trucks. Also I would check all of your vacuum lines, when I first purchased my Bronco off of an auction lot many of the lines had dried and cracked and I didn't get much response when trying to control the A/C.

 

[seakey]

There is a little blue plastic clip on top of your heater control that holds the outer skin of the cable to your mixing box this small clip is a POS when it brakes the whole cable will move and not the center and the heater will stay in whatever its stuck on. This clip is unavailable from ford just glue or rig it up unless you want to buy a new heater control unit cha ching$. This will cause said problems also cheak hoses and heater core( behind glove box). I dont know what year your truck is but my 90 uses cable acctuated control. Oh yea if this is your problem lubricate cable while you are there with dry graphite lock lubricant. Good Luck

 

[Jonathan]

I had the exact same problem last spring. Had a dip in the temps, turned the heater on and only had cold air. It had worked all winter. I thought I would wait until the weekend to start investigating, tried the heater again the next day and it was my heater core. Of course it completely blew at that point and the cab flooded with antifreeze. Easy swap out though. It was inexpensive and I was able to access it by removing the glove box. Good luck.

 

[miesk5]

Bob, you have a 96?

Air Conditioning Controls for '92-96 A/C by Steve83

if so, ck blend door for bad/broken hinges, or warpage or obstruction

Temperature Blend Door/ Control Cable Location pic for 92-96 Bronco & F Series pic Source: by Steve83

go thru the List in top Link by Steve and see what's going wrong.

GL!

 

[bobob]

Guys,

Thanks for all the info. Turns out the heater core was clogged. I was able to unclog it with my garden hose flushing it in both directions.

Thanks Again, bobob