06 6.0 fan clutch stuck in engaged position. So I changed the fan clutch it doesn't stay engaged anymore. comes on during startup and gives the appearance that the batteries are dying. Stays on for about 10 minutes when first driving then goes off. If I run ac it comes on at every light and it doesn't matter what engine coolant temp or oil temp and they are all within 6 degrees of each other. I'm thinking maybe the AC is a issue or bad sensor somewhere. No codes everything seems to be functioning. When I say comes on it's on high speed roaring.

 

Does it look like the wiring has been rewired on the engine harness side?

 

It's not unusual for the fan to be locked at startup if it was when you shut down, but 10 minutes would be excessive. The locking up at every light issue is probably related to the AC pressure switch.

These can be stored incorrectly and cause them to fail right out of the box, you need a scanner that can pull fan speed and clutch duty cycle to compare the commanded DC with the fan speed ramping up. DashBoss, ScanGauge and IDS do it, not 100% sure what else does. Edge Insight doesn't.

 

Buy a 7.3 fan clutch adapter from Bulletproofdiesel and a 7.3 fan clutch to eliminate electronic control and make your truck run cooler. Best thing I've done yet.

 

I put in a new ac pressure switch I drove it fan clutch turned off in about 60 seconds and came on 1 more time during my short drive. I didn't drive it for a long drive yet. Ac seems to be functioning alot better seemed colder than normal... Thanks for all the info I really appreciate it. I will let you know how it ends up I'm definitely doing the bulletproof fan clutch adapter change to remedy the issue...

 

You will need the Bulletproofdiesel 6.0 to 7.3 fan clutch adapter and a 7.3 fan clutch. I bought a Murray fan clutch made in USA and it has been flawless. I can't hear the notorious "roaring" everyone talks about but maybe it's because of my straight exhaust. Coolant and EOTs dropped as soon as I did this mod.

 

How hard was it to do the pressure switch? I've been trying to address a long-running AC "issue," and when I tried to locate the high-side switch on my truck, I needed three elbows to reach it.

-blaine

 

The vacuum operated A/C switch that closes the valve on your coolant line to the heater core is right behind the alternator. I just put a manual ball valve in it's place to shut off hot coolant from running through the heater core because those vacuum operated valves never close all the way and allow hot coolant to knock down the efficiency of your A/C. The A/C works much better and all I have to do is open the ball valve this winter.

 

That's already been addressed. The one I'm talking about is in the high-pressure line from the compressor to the condenser. The PCM monitors this one to supposedly know when to increase the fan speed when the high-side pressure passes a predetermined limit.

My truck's AC is reasonably competent when cruising on the freeway. But get shut down in one of Austin's notorious traffic jams, and it just about stops working. It's been this way since about two years old, so I'm thinking that either the pressure switch is borderline, or the programming is screwed. One I can do something about, one I cannot.

-blaine

 

My Excursion does a similar thing. Sometimes it will freeze you out and sometimes it's just enough to keep you ok. I'm interested in how this pans out.

 

That's why the 7.3 fan clutch adapter nut and fan clutch are a great mod. The adapter nut threads on your water pump then has threads that fit the 7.3 fan clutch and the fan clutch bolts on your existing 6.0 fan blades. The 7.3 fan clutch is not controlled by the computer so it comes on when it is supposd to no matter what. I paid about $60 for the adapter nut and $90 for the 7.3 fan clutch.
Check this out:
BPD 7.3 Fan clutch adapter review - Ford Powerstroke Diesel Forum

 

It wasn't hard at all took about 10 to 20 minutes.

 

A/c works better than ever. Fan clutch still engaged more than normal only when ac is on and on surface streets on freeway it works normal seem like my trouble are low speed with AC on. I am going to have to do the bulletproof conversion...

 

For the record, that's the low-side switch.

The PCM monitors both high side and low side pressures.

If the high side pressure gets too high, it ramps up the fan, and then ultimately disengages the compressor, to keep from blowing the system up.

If the low side pressure gets too low, it disengages the compressor; mostly to keep the system from freezing up, but also to keep the compressor from damage due to low refrigerant/lubrication.

Hazarding a guess, the computer was seeing the low side pressure too low, and keeping the compressor off.

-blaine

 

Thanks for the correction do you think both high and low side could be going bad together. I put gauges on it the pressures seemed high at first then stabilized to normal after it ran for a few minutes.