Air Conditioning Slow to Start

[creekman]

When the car is cold it takes 5-10 minutes of driving before the compressor clutch engages, then good cold air.  However once the car is warm up and you stop, then restart the car the A/C comes on immediately.  We've installed a new compressor clutch and there's voltage to the clutch?

 

Anyone have any suggestions on what is going on...

 

Thanks,

 

Mitch

[DBJoe996]

Is your ambient air sensor located correctly in the front bumper?  Also, there is a interior temp air sensor located behind the little plug on the passenger side on the dash.  I would check that too.

[creekman]

Joe,

 

Interesting, I wasn't aware that they were tied into the A/C system.  Yes on the front sensor, I thought that was the outside air temp.  How do you check these 2 sensors?

 

Thanks,

[DBJoe996]

I don't know of anyway to actually test them other than does the ambient air temperature read correctly on cluster?  The HVAC system uses the temperature differential readings between the outside air and cabin air when you use AUTO setting on the HVAC control panel.  The system then cycles on/off the AC compressor as needed for the desired cabin temperature.  The way to get around that is to manually set the fan controls/temp.  The second thing that I have heard/read about is a sticking or faulty pressure switch causing delayed AC.  Part #21 here  http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=813-25

 

 

[DBJoe996]

One other thought - when you switch on the AC, do both radiator fans come on low or are they delayed as well?  And when the AC does finally start working, are both left/right radiator fans coming on?

 

There is also an AC compressor relay in Relay Support 2.  Might think about replacing that relay to eliminate a potential problem.

 

[creekman]

Joe,

 

I really appreciate your help, I'll pursue each idea, I never thought that the system was so cross involved with so many other components. What happen to the ole' days when you had one switch for one system...

[creekman]

Joe, where is this relay (s)?  What you're suggesting is replacing No. 4, A/C Compressor?  Again thanks for the help...

[Loren]

Under the carpet behind the back seats - next to the DME .

[creekman]

Thanks Loren,

 

I was afraid of that, I have a back seat delete so it's a little work getting the hinged package tray out of it's resting place...

[Ahsai]

How is the pressure of the refrigerant?

[creekman]

It's good, I can't give you the numbers, but my guy was happy with it...

 

Thanks for your reply,

[Ahsai]

Indeed a strange problem.

[creekman]

No kidding...  I am going to change out the Compressor relay and check the radiator fans to be sure they're cycling correctly.  My immediate problem is finding out why my 3rd brake light isn't working.  I failed my safety inspection so I need to get that fixed, PDQ.  See my post on that...  

 

Thanks again,

[creekman]

We changed out the Trinary switch which is located next to the A/C charging ports.  But no joy...  I have the A/C relay that goes under the back seat, but

I have a back seat delete so its more involved to get to the relay.  However all my experiences have been either a relay works or doesn't.  The system works great,

but I might have to live with this until I can figure it out.  The only trouble is here in Texas you don't want to wait 10 minutes for cold air when it's a 100 degrees on a hot August day.