Blend door help

[Bamadude]

Read quite a few posts and have not found what I need to date. Can anyone suggest
anything further? Heard a clicking noise for a week or two behind my glovebox when I cranked my car. I noticed my heat would not turn on. Just blowed cold air. I bought a 640-400 Dorman (think that was the part number) and replaced it. Still blows cold air. I researched and saw where you could oull the fuses and crank car and run for a couple then shut it off and reinstall fuses to reset ac system. The only fuses I could find related to ac was in engine compartment-one was a 10a bus type mini and another a larger block. After reinstall still nothing but cold air. O more clicking with new part, air is switching between top/botttom but still blowing cold. Anyone got any other suggestions to try? 2012 manual fiesta.

 

[Handy Andy]

This is a long shot, but after what you have listed you tried, there are few options left.

The main issue I see in this is either:

• Something jammed the heater valve
  • This may mean a trip to the service department
    • Low Radiator coolant (unlikely)
    • Replaced wrong actuator - there is another one buried in the back not at the "recirculating air door" but near the carpet - and requires some console trim to be removed as well as the Glovebox door to develop a reach for and access into - inspecting the section.
    • Cabin Air filter plugged or jammed when replaced - air arrives past the core so no exchange of heat can be made - comes thru vents or a cracked clam-shell the climate unit is in. I've seen the air filter cover replaced and re-screwed in so that screws actually punctured a harness - killing the power to the doors in that section.
    • Fuses located in the internal Passenger compartment fuse block can also have fuses affecting the blower

​

Best way to see if the heater is even giving heat is to check the hoses back in the engine compartment - the ones that route to the rear of the engine and go to the firewall, those hoses one would be hot the other would be cold or cooler - signals that the core is not circulating the heat from the motor (blocked) so the valve that controls that - means a trip to the service department. IF both are hot (means open) - again a service trip because the entire climate system the core rests in is not exchanging that heat out of it.
Gotta' get back to work - so I'll help more as I can - others can feel free to chime in anytime!

 

[Handy Andy]

To add a little more...

Did you look under the Glovebox - as it try to pin-point the click click?

In Fiestas - they use a Body control module to handle a lot of stuff the older ECM - now PCM - did as one unit - they broke down the car into a Venn Diagram of overlying interactions of Body parts, which are kept from the Engine Parts and settled for "What's Parts is Part's" approach and made the BCM control the lights, fuel - brakes and even the radio and it's dashboard - while the PCM simply focuses on the Engine and at times, Drive Train - while another module called TCM took over the automatic transmission.

The rest of the unbeknownst stuff winds up in the Dash board Pods and other whatnot's they call "features" wound up as various "modules" you don't know about and they won't tell you what it is and why it's there...

Ok, back to the BCM.

It's located on the firewall in the passenger compartment - right by the Cabin Air Cleaner and the Recirculated and Outside air - door assembly.

The BCM handles Fuel pressure so it uses a relay in earlier models and in the latter ones, they switched to Solid State modules - to handle the Fuel pump and pressure regulation demands.

Those earlier ones had relays that carried their mechanical apparatus noise (transferred it) into the car by having that box with all those connectors sealed with those relays inside it - clicking away as you idle thru the moments in time when the Fuel pressure in the fuel rail was at a maintain point that made those relays click more or less in a 2~3 second pause as time passed - slowly - making matters worse was those times when you're running silent and the clicks seems to turn more into a clackitty clack

​

The photo above is what you'd see when you go under the Glovebox - you see this when you look up from the floorboard - the BCM is BOLTED to the firewall and can be a source of this noise.

You can verfiy that click-click is from here, by placing your hand on the module as the engine runs and you can feel the relay click vibrate into your hand from the module - if this is where that sound seems to be coming from, don't worry, it's normal.

 

[csigona]

Bamadude, did you ever get this fixed? I'm a month late here, but I can offer my own blend door experience. The clicking noise comes from a slipping gear inside the actuator. Two things can cause it to slip. The first is that some of the gear teeth are broken; the second is that the gear is sloppy because the hole in which it's mounted is too big. When I started diagnosing the click, I also went down the electronics trail, but the answer turned out to be purely mechanical. I bought an aftermarket actuator from RockAuto, which immediately failed. I complained and they sent me a replacement, which also immediately failed; same with a third from a different manufacturer. The solution was to get an original Ford part. I pulled one from the junkyard, which works well.

Note that you can run tests by connecting the wire to the actuator, but not mounting it. Just fiddle with the HVAC controls and watch the gear turn.