2017 S550 3.7L V6 A/C Troubleshooting

[BamaLandYacht]

New to the site, joined for hopes of insight on our 2017 S550 A/C issues before I take it to a service shop or the dealer.
I’m fairly well mechanically inclined and have performed the following testing as follows



7.5A fuse in passenger kick for interior cliamte controls verified


10A fuse in position 23 for ac compressor verified


A/C relay verified by swapping for horn relay


A/C compressor Clutch manually powered by bypassing relay with engine off to verify working clutch engagement on compressor

I'm in the process of either buying, renting, or using a lent pair of decent ac gauges this weekend to verify pressure

The condenser fans run constantly non stop since the issue originally started.

in my eyes I’ve narrowed it down to low refrigerant, bad pressure switch or… god forbid a expansion valve witch if is the case I’ll probably sell it lol.
If anyone has anything I might of missed or any suggestions I’m all for positive or negative feedback!

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[MrMike]

If the evaporator was never replaced, I vote leaky evaporator. Mine had the same symptoms.

 

[ORRadtech]

If the evaporator was never replaced, I vote leaky evaporator. Mine had the same symptoms.

Seeing the model year of the car, that was my first thought as well.

 

[BamaLandYacht]

If the evaporator was never replaced, I vote leaky evaporator. Mine had the same symptoms.

I know about 5 years ago the A/C condenser radiator was replaced at the dealership for tanking a brick piece on the interstate

 

[MrMike]

I know about 5 years ago the A/C condenser radiator was replaced at the dealership for tanking a brick piece on the interstate

That's the piece by the radiator. The evaporator is inside.

https://www.mustang6g.com/forums/threads/a-c-evaporator-replaced-due-to-leak.136187

 

[BamaLandYacht]

That's the piece by the radiator. The evaporator is inside.

https://www.mustang6g.com/forums/threads/a-c-evaporator-replaced-due-to-leak.136187

Yeah I was aware, just wanted to state that the condenser radiator had been the only thing ever replaced on the a/c system.
I’m hoping that I can get my hands on a set of gauges in a day or two and I’ll give a update!

 

[MrMike]

Yeah I was aware, just wanted to state that the condenser radiator had been the only thing ever replaced on the a/c system.
I’m hoping that I can get my hands on a set of gauges in a day or two and I’ll give a update!

Gotcha, good luck man. It's the only problem I've ever had with the car. It's been good since the new evap thankfully.

 

[ORRadtech]

Yeah I was aware, just wanted to state that the condenser radiator had been the only thing ever replaced on the a/c system.
I’m hoping that I can get my hands on a set of gauges in a day or two and I’ll give a update!

Harbor Freight sell a decent set for like $65 if you're into owning your own tools. I don't use mine all that often but they're invaluable when I need them.

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