No AC in 4200 any way to verify if cutch is working?

T

TKoos

Junior Member
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50
Hi,
First post from me here. We bought the Maserati ten days ago or so, she's in brilliant condition being a 2004 with only 5500 km.
Our problem is that the AC does not produce any cold air. The weather was cold when we bought her so we couldn't test the AC.
I think that I've checked everything I can imagine, the fuses are good, the AC-relay is good, I put a hair blower to the interior sensor, a self test gives only AA-00 etc.
No matter what I do the AC clutch never engage. I can turn it by hand, and it feels like it's rotating freely. I'm not a AC-technician but I thought that it should be a bit more friction involved?
My question is if there is a pressure sensor that cuts of the clutch to spare the compressor if the system is running out of refrigerant?
The car has been stored in a garage for the last six years so a slow leak sounds reasonable to me.
Anything else I should try before I take the car to a workshop to fill up the AC?
 
Zep

Zep

Moderator
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9,312
Welcome to the forum.

There is a combined high pressure and low pressure switch, it is fitted to the union that attaches to the drier. If the pressure is below 2.75 bar, the clutch won’t engage.

Your best bet is to have the system pressure checked.

85291
 
T

TKoos

Junior Member
Messages
50
Great news, thank you Zep!
Of course a heap of other stuff can be broken too, but I'll live in good hope until tomorrows workshop verdict. :)
 
Zep

Zep

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TKoos said:
Great news, thank you Zep!
Of course a heap of other stuff can be broken too, but I'll live in good hope until tomorrows workshop verdict. :)
Click to expand...

You are very right, but with a bit of luck and a following wind you will be fine. If you do find it has been void of gas for some time, do replace the drier before having it gassed up. It will be saturated by now.

Oh, and post pics in the newbie section so we can admire your new car!
 
T

TKoos

Junior Member
Messages
50
Ouch.
You have any clue how low pressure it can hold without saturate the drier?
Replacing the drier sounds expensive. How do I know if that is necessary?
(And it's probably located somewhere that forces a complete relocation of the centre-console, both doors and the gear box?)
Pictures will follow when the winter has left us, we've had 3 degrees and rain for the last week now. :eek:
 
T

TKoos

Junior Member
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50
Sounds promising. What would the symptom be if the drier needs to be replaced? Not overly expensive too. Nice surprise :)
 
Zep

Zep

Moderator
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When they get saturated it stops taking moisture out of the refrigerant. This then circulates, reducing capacity and potentially freezing in unhelpful places.

The symptoms will be reduced cooling capacity and and erratic supply temperature. Long term it can cause corrosion and failures.
 
safrane

safrane

Member
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16,896
Check the bearings on the AC unit, any movement may indicate its knackered... and its better to fix now rather than when its hot and you are 1k miles from home and don't speak the language well enough to explain (yes I'm still mentally scared Zep)
 
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Zep

Zep

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safrane said:
Check the bearings on the AC unit, any movement may indicate its knackered... and its better to fix now rather than when its hot and you are 1k miles from home and don't speak the language well enough to explain (yes I'm still mentally scared Zep)
Click to expand...

Well, it was some fun and games wasn’t it!
 
T

TKoos

Junior Member
Messages
50
safrane said:
Check the bearings on the AC unit, any movement may indicate its knackered... and its better to fix now rather than when its hot and you are 1k miles from home and don't speak the language well enough to explain (yes I'm still mentally scared Zep)
Click to expand...
Thanks for the advise!
 
T

TKoos

Junior Member
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50
Follow up after the visit to the workshop. The system was lacking some 500 g of r134. They vacuumed the system for some time and filled her up with 750 g. The clutch started to engage almost instantly, after 15 minutes it produced cool air again. It took half an hourish to fill her up.
I will keep an eye on the temp for some time, but hopefully it was only leaking from being underused (not at all for six years).
 
Zep

Zep

Moderator
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9,312
TKoos said:
Follow up after the visit to the workshop. The system was lacking some 500 g of r134. They vacuumed the system for some time and filled her up with 750 g. The clutch started to engage almost instantly, after 15 minutes it produced cool air again. It took half an hourish to fill her up.
I will keep an eye on the temp for some time, but hopefully it was only leaking from being underused (not at all for six years).
Click to expand...

This is the best news you could have hoped for. Still some gas so probably no issues with the drier.
 
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