Air conditioning not working

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

dillard09

FRF Supporting Member
Supporting Member
Joined
Nov 23, 2013
Posts
1,247
Reaction score
1,507
Location
College Station, TX and Socal
So I was driving the other day and all the sudden my AC quit blowing cold air. Of course it was 4pm in Texas so it was like a suana at 110 outside. Took it home and checked the freon and it was around 100 on both sides when truck off. So I had the system pulled down to zero. Put my AC vacuum pump on it and pulled a vacuum on the whole system for a couple hours. Turned it off and it held the vacuum for around an 1hr. So no leaks. Got my cans of R134A and started to fill with 31 Oz as required but after about half a can (6-8oz) both the low and high are around 100psi but the AC clutch won't kick on. I checked all the wiring and everything looks good. I don't know what it wrong or what to do. Don't want to take it to a station because I like to work on my vehicals and want to know how to do this.
What's the AC pros out there think?
Why won't the clutch kick in?
How do you get the AC clutch to kick on so I can fill the system back?
Is the compressor bad?
I'm mechanical inclined and can turn a wrench but I'm clueless to AC systems.
Thanks for the help in advance FRF.
Jake
 
OP
OP
dillard09

dillard09

FRF Supporting Member
Supporting Member
Joined
Nov 23, 2013
Posts
1,247
Reaction score
1,507
Location
College Station, TX and Socal
The battery didn't change anything.
So I drop my skid so I could get my arm up into the engine bay where the AC compressor was. I'm not able to turn the outside of the clutch by hand with truck off but it don't spin with the truck and AC on.
 

FordTechOne

FRF Addict
Joined
Jul 29, 2019
Posts
6,435
Reaction score
12,575
Location
Detroit
The first step in diagnosis, before even checking refrigerant pressures, is to check for DTCs and view live data. The A/C compressor relay is controlled by the PCM, so if the PCM is seeing incorrect/invalid readings and/or has set a DTC, it will inhibit A/C operation. A common example of this is an invalid or skewed pressure transducer or temperature input.

There is also a PID that indicates whether the PCM is commanding the A/C on. If it’s being commanded on and not engaging, then you can move on to the relay, wiring, clutch, etc. There was a potential issue with the A/C clutches on some early models, what is your build date?
 
OP
OP
dillard09

dillard09

FRF Supporting Member
Supporting Member
Joined
Nov 23, 2013
Posts
1,247
Reaction score
1,507
Location
College Station, TX and Socal
Sorry brother. You've done all I'd try. Hopefully @FordTechOne or @Old-Raptor-guy, or other with more knowledge will drop in. ACs and carburetors have always been black magic to me.
Thanks! I hear ya! Was hoping one of those 2 would chime in. Might dig into more if it wasn't so darn hard to get to. Pain in the ass!!
 
OP
OP
dillard09

dillard09

FRF Supporting Member
Supporting Member
Joined
Nov 23, 2013
Posts
1,247
Reaction score
1,507
Location
College Station, TX and Socal
The first step in diagnosis, before even checking refrigerant pressures, is to check for DTCs and view live data. The A/C compressor relay is controlled by the PCM, so if the PCM is seeing incorrect/invalid readings and/or has set a DTC, it will inhibit A/C operation. A common example of this is an invalid or skewed pressure transducer or temperature input.

There is also a PID that indicates whether the PCM is commanding the A/C on. If it’s being commanded on and not engaging, then you can move on to the relay, wiring, clutch, etc. There was a potential issue with the A/C clutches on some early models, what is your build date?
Was hoping you would chime in.
I have checked for DTCs and I have none.
It's a 17 with build date 11/16.
 
Top