AC Problems!!!!!!

[goats]

Most fords I've had the low psi switch go bad on them

[texasaggiesrocks]

how much do one of those lower pressure switchs cost?

[md18]

The blend doors on these trucks are electronically controlled. That being said the most common reason for poor cooling is the system being low on refrigerant, the compessor clutch not engaging, poor fan clutch performance not getting enough airflow across the condensor at idle, or the cycling clutch switch (aka low pressure switch) going bad.
To start, NEVER try to charge an ac system without a manifold gage set with both low and high side gages on it. Using those wally world one gage wonders is like flying blind. The high side pressure tells you a lot more about whats going on than the low pressure side.

Usually a ford leaks at the springlock couplings and the compressor shaft seal, random oily residue around an ac fitting is usually a sure sign of a leak and also if you see a ring of oil slung around the compressor clutch area (hood, radiator hoses, etc) thats a good sign also.

Fan clutches and poor airflow problems can be checked pretty easily if you have hig and low side gauges, when its really hot out let the truck idle and when the high side starts to really climb (250-300) spray the condensor with some water and if it drops really fast then theres an airflow problem.

The low pressure switch is pretty common also, this can be easily diagnosed by looking at the compressor hub while the ac is on and its blowing hot. If its not turning, theres a problem! First try to take the handle of a hammer and tap the hub in, if it pulls in then it needs to have a shim taken out fron under the hub. You can try to wiggle the connector and see if it comes on, be sure to check for broken wires at the switch. If it doesn't and you have adequate low side pressure (over about 40 psi should kick it on) then it should be replaced.

This should take care of most superduty ac problems, maybe even should be made an article lol.

[DJM]

Dieselsite makes an upgrade kit for the A/C Mine does the same thing as your guys trucks are doin might give the kit a shot not sure if it's a sure fix but couldn't hurt.

[MudRulzz]

I just resolved a problem with the ac working only 5 percent of the time, more often it worked at idle. I ended up solving the problem by removing the shim, replacing the low pressure switch, and I had a bad high pressure switch connector. If you pushed the connector down, the clutch engaged, but leaving it alone it was very intermitent. I resolved this problem by taking the connector apart (making sure to note which wire went where) and gently squeeze with pliers a little at a time while test fitting it.

If you want to check the low pressure switch, first, make sure that the system is properly charged with refrigerant. Disconnect the connector on the low pressure switch, and stick a short jumper wire across the connector. If the clutch engages then the low pressure switch is likely the problem. DO NOT drive it around like this.

[jsticher]

I have had the same a/c issue's as several others have had with the a/c only working at higher rpms or when there are cooler temps outside. The a/c clutch seems to be the solve for me. I used a c-clamp to lock the clutch up to the pully to remove the center bolt and then a screwdriver to gently pry the clutch out enough pull the clutch off the center shaft. there was a small washer between the clutch core and coil that I removed to get the gap smaller. before doing the above steps I waited till the compressor was not engaged and blowing warm air from my vents, then I lightly tapped the clutch in and it snapped right to the coil. This was my indicator that the clutch was wore out. I confirmed it by removing the washer and getting the clutch closer to the coil. New clutch hub at Oriellys is $35. 10 minute fix.

Joe

[jakesnake_sxr]

im having a problem with my air blowing out the defroster. I had ford pull all the work ever done to my used truck and in 07 it had a vacume pump replaced. im pretty sure that it is the same issue here. I am looking for any info that might help me test this theory and or repair this issue. thanks

[jsticher]

if your air is blowing out the defrost all the time you probably have a vacuum leak. It will default to defrost if you lose vacuum. Mine defaults to defrost when I engage 4 wheel drive because the orings are leaking at the hubs. It will return to normal after I turn the 4x4 off and the vacuum system catches back up.

Joe

[jakesnake_sxr]

what would you reccomend i do to check. i have pulled the glove box and manually moved the gate actuator and got the air to blow out of a diffrent vent. but not real sure how to check the vacume pump prior to spending 210 plus tax from the ford house, just to check the pump. any ideas?

[jsticher]

does it blow through the defrost vents full time no matter what?
If so then you need to start tracing lines from your vacuum pump out and find where you are losing vacuum. The other thing is the vacuum pump itself, is it working properly? is your truck equiped with 4x4? Are your hubs vacuum powered? or were they and some one swaped it to something else and did not properly cap the vacuum line? I did have one time that my ac did not want to switch back after using 4x4, I ended up squirting some light oil down the vacuum lines to lube the different orings in the system. seemed to help after a little while. I haven't had a full time defrost blowing issue like yours but these are the places I would start.

Joe