06 truck stock except for a 40 tune on the FICM. AC stays running on all but floor vent. Switches between vents, floor, defrost just fine. Vacuum works. Heater valve stays shut even when switch is set to max hot and hi and low vents. Disconnected vacuum hose and plugged it for the heater valve and got not freezing cold air out of the floor vent. Heater core is hot to the touch but the AC is running and blowing cold air.

Switch has a plug with 3 wires on the back. Any idea if this sounds like a switch issue or is it somewhere in the wiring?

 

Can anyone at least tell me if there's a difference in the 04 and 06 trucks? My manual covers up to the 04 and the pinpoint test for the **** didn't ohm out right.

But I know they made some changes in 05 and don't know if this part was affected.

 

https://www.ford-trucks.com/forums/1...-problems.html
try this is your grey vacuum line hooked up under the hood? also under the glove box is a chrome canister check and see if things are plugged in. the link is for 4x4 I for got to look to see if your was or not

 

Yes this is for a 4x4, but it's not a vacuum issue. I don't recall seeing a chrome anything behind the glovebox. Just black plastic, but the door moves to switch air between vent, floor & defrost just fine off vacuum. The heater shut off valve is always on (from vacuum) and the vacuum pump works, but doesn't run constantly (indicating there's not a leak).

Thanks for trying to help though. That's the most I've gotten so far.

 

trying LOL, does the 4x4 activate from cab? I believe it's all hooked from the same vacuum, the canister is not behind, lay on the floor board and shine a light upper left at least mine was chrome looking and the grey Vacuum line runs into it.

 

Yes 4 x 4 works fine.

And next time you want to look up behind the glove box, pull the stuff out of the glove box and just pinch the sides inward. The door will open and fall all the way to the floor so you can see everything behind there without laying on the floor.

 

I think I new that, one problem too much crap in the glove box faster to lay on my back then when my wife come's out I can wake up and act like I'm working on something I'll dig up something else for you in a bit to Ponder

 

Can you tell if the blend door is moving full sweep? Maybe it's binding somehow. If you haven't noticed there is a similar thread here : https://www.ford-trucks.com/forums/1...il-i-move.html . Post #13 has a description of operation that may be helpful to you.

 

Thanks for the link. Post 13 is interesting, and it makes me wonder more about the ****, or whatever is between the **** and the doors.

The select **** that switches between ac, vent, floor, etc. works just fine and the ac compressor comes on at the appropriate times and off at the appropriate times.

The problem is, even with the AC off, the warmest I can get is ambient temp coming out of the vent.

 

I recall the early and late SD trucks are different in how they operate the doors. The thread Rusty linked above has that info. I believe there is one door that operates via electrical motor on certain models.


I've slept since I learned all that info, so I don't really remember.


If you wanted vague information on the heater operation of the SD pickups, I'm your man. Hopefully the thread linked above will shed some light.

 

I do believe there is a second, electrically actuated door on the 06. I think I've even found the actuator, but I can't seem to figure out how it works. Usually there is an arm that you can visually check or manually manipulate to see what's going on. I'm couldn't find any arm on the thing I found.

Failing the ohm test on the **** bothers me, but I really need to know if the test is the same for the 04 as it is for the 06. Does no one here have a service manual or dvd?