i am still trying to diagnose my no ac until engine reaches operating temp, or i am moving.
i have come to suspect a bad fan clutch.
when the engine is at full hot operating temp (205 degrees) the fan clutch should be locked up and i should not be able to spin it by hand with engine off key in run position, correct?
and if i put 12 volts to the clutch, it should also lock up an not spin by hand?

 

No, when the engine is off you can always spin the fan, but there should be some resistance.

When you put 12v to what clutch, the compressor?

 

fan clutch.
with key in run position but engine not running and 205 engine coolant temp, the fan clutch should be locked solid..rite?

 

Radiator fan clutchs never completely lock up. There is no power to it on our trucks at least. If you can spin it easily when it's hot it's probably toast. Also if it has any looseness.

 

The 2011 and newer trucks use electric fan clutches.

 

Be good to have more info on what is being worked on.

 

Points to you.
I thought this was posted in the 6.2 engine forum.
2014 F250 supercab 4X4 6.2 engine

 

The cooling fan is PCM-controlled. Use a scan tool to see what the PCM is telling it to do and what it is detecting as to its status.

Same for the compressor clutch.

 

what and where would i look for in forscan or torque pro?

 

The fan is electrically controlled, not electrically driven. The clutch is not the same as an A/C clutch. it's more like a torque converter/viscous clutch. The electronics open and close a valve that allows the viscous fluid into the fan clutch. This causes drag between the input and output sides of the fan clutch and results in the fan side spinning. when the valve is closed the fluid is pumped back into a reservoir and the drag between the input and output side is reduced and causes the fan to spin less. The electronics meter out the fluid to get the fan to spin at the desired speed.

 

First questions out of the parts mans mouth is what are we working on today?
Yes those electric clutches will lock up 1:1
They also have a duty cycle to run them at any desired speed
That said the A/C should still work without the fan for a short time then turn the fan on when it needs it
You need a scan tool to find out why the A/C compressor is not running on initial cold startup
It doesn't need that fan until the engine gets hot
The processor might turn the fan on in certain instances regardless of ECT sensor voltage
That means if the processor does not see the clutch fan return signal saying it is engaged it may not feed power to the AC clutch (ground the relay)
You need a scan tool and an up to date ford tech
Try fordtechmakuloko on youtube and ask him the same question
Two heads are better than one
If the above is the case. I think your clutch fan has failed

 

the problem is NOT the clutch.
new clutch installed and it does the same thing.
scan tool and ford dealer diagnostic computer can not figure out what sensor is bad.
this all started when a cat got into the engine bay between radiator and fan and could not get out. when i started the engine it was stuck between fan blades and ripped all the wiring and vacuum hoses off the passenger side of engine, fan wiring, and destroyed the shroud.
everything bad was replaced, and then once it got warm and ac was needed,, this started. the compressor runs and ac works as long as you are moving and air passes through the condensor. . the fan does not engage until the engine reaches operating temps.

 

Damn sad about the cat
You may need to visit a different dealer if they cannot figure it out where you went
Maybe all the needed torn out wiring did not get replaced?
Maybe the processor driver for the AC clutch relay got shorted out and burned?
Once again a scan tool with an up to date tech is what you need

 

The ECM determines when to run to engage the fan clutch and what speed to run it at. It uses a bunch of inputs to determine this. The service manual does not have the details on how the pcm determines when to turn on the fan. I'm not sure if it will generate a DTC if the fan speed is not what its calling for. Might only do it if the fan speed is to low. All the sensor data can be read live, so if one is bad it should be pretty easy for a dealer tech to figure out which one is not working correctly. they could compare it to another similar truck. But I would guess a DTC would come up if a sensor was bad. Have you had the a/c system checked to make sure the correct amount of refrigerant and oil is in it? Another guess is something got crossed when replacing the broken wires, but I would guess it would have a DTC in that case. Maybe one of the a/c pressure sensors is off.

 

Absolutely
Yes +1 what whagen said
They do not tell us techs what speed at what temp like the old days
You must rely on pids and be familiar with what is correct for each different Ford vehicle
I agree on the wires being possibly mismatched when reconnected
The codes should be there for fan operation and AC clutch malfunction if that is the case