Any coaching on air conditioning common points of failure?

Hello - hope everyone is doing well. My Mondial from BaT showed up with an undisclosed air conditioning failure. Blower works but only warm air. Putting aside the issue of it not being disclosed are the reasons any common failure points to be aware of?

Would you recommend a Ferrari specialist or air conditioning specialist? Assume Ferrari but if this is “just” widely used parts common to many cars that comprise the system maybe not.

Thanks!

 

Ferrari will say to you = you have to live with it....so go to a AC specialist.

 

The later Mondials use a common Sanden compressor, but with a special clutch that is fairly unique to the Ferrari. Both the compressor and clutch can fail. The system used the old r12 freon. Can be converted to r134, but the old long hoses will diffuse some r134 and need an occasional top up. If yours was converted to 134 it may simply need a top up charge.

There is a fairly common dryer used in the system, and the condensor is unique to Ferrari but accessible and repairable if there is a leak. The compressor ports can only be accessed through the right wheel well, so there is more labor to get at the system to check and recharge than in cars where the high and low ports can be accessed in the top in the engine bay.

An ac place should be able to handle the system. There is nothing truly Ferrari specific to the system as a whole which a tech servicing eg. German cars would be confused by.

There are three relays under the dash in the center, which relate to the ac and heater system. You might just have a failed relay that clicks on the ac when the pushbutton for air circ is pressed and the temp is set to cold which turns the fan on. Worth checking this, there are some threads on the Mondial heater system controls which will show you which relay would affect the ac.

My 1988 Mondial was r134 converted by a local gas station, after I acquired and installed a new compressor and a new dryer.

 

Super helpful information gentlemen, I very much appreciate the coaching. Let me do some checking on the relays and report back.

 

In my case, the a/c technician was able to get the service ports through the engine bay, but it's not super accessible.

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The middle of the three underdash relays is the one that relates to the AC clutch. The relay to its left is the same type (it is for the for the highest speed setting of the fan control) so you could switch them and see if the ac clutch actuates.

You probably have an original Italmec relay, the Bosch replacement part number is 0 986 AHO 251.

There is actually a micro relay in the small ac computer brain that actuates the clutch. So there is a Ferrari specific Bosch ECU that could also fail, but that seems to be very rare.

 

That micro relay did fail on mine at one point.

 

Andy / Urs - I am searching for a replacement dryer for my 85 euro mondial QV which has two switch ports...Other than buying what should be a $35 dryer for 145 pounds from SP, the closest I have come is this and it's not correct: https://www.polarbearinc.com/index.cfm/category/289/ferrari.htm.

Do you know a source? Interchange? - Thank you!

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Is this the same for all Mondials or just the T?

***Speaking of unique things about the Mondial AC system , isn't the Sanden compressor for our cars designed to turn counter-clockwise instead of clockwise like most Sanden compressors due to the way it's mounted and run with our motors? Also, isn't there some guidance that the AC should be recharged while the car is idling at 2500ish RPMs? Those are a couple of the items off the top of my head that I remember reading was different about the cars.

2cam

 

I think the relays are the same for 3.2 and t's. Not sure about earlier models.

The original Sanden on my car was model SD-508. The replacement was the same. Not an uncommon unit, used on eg. Saab and other cars of the time. I can't recall the direction it rotates, I will have to take a look.

Charging with the engine throttled higher than idle will charge faster, but I don't think that is special to the Ferrari.

The guts of the Ferrari Mondial 3.2 ac system is a common system widely used, with some proprietary heater/ac switches and controls (although even some of these appear to be in common with some Mercedes and BMW's and other Euro cars in period).

 

In my 3.2 this dryer is mounted. By the number it seems that it is also mounted in farm trucks.
It's ready for a replacement.


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Thx for the confirmation on the relays!

2cam

 

Just read the 'manual' and it seems to indicate you should not turn the AC on or off while the engine is running or when it is 'cooling'? Has anyone experienced a problem with this?

 

My AC dose not even go on. Hit the button and nothing. Heater works but ac is a no go. Where are the relays for the “t”?


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Congratulations for your new car!
The Mondial's A/C hardware as in the compressor/clutch/hoses/condenser/dryer/evaporator hardware is nothing particular other than the reversed direction of rotation of the compressor/clutch.

It's temperature regulation via the electrical/electronics however is Mondial-specific,

Any A/C shop can take care of the hardware side of the AC.
If you encounter a A/C control issue, it's Ferrari or anyone who can read my diagrams.

 

Not on mine - accessible from the top no problem:

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Thank you for the replacement part number. If you use a regular Bosch relay, you need to relocate a pin for things to work.

 

Joe - what is the second switch port for? The original one I got from Eurospares only has got 1 port.

 

No, not Ferrari-specific; all SD-508 can turn either way because they employ straight-cut gears.
And yes, the do turn "the other way" from most cars, so the clutch is Ferrari specific because of it and the belt section used.

To cut noise, the newer compressors use helical gears and can only be used in their design direction.
The same form factor compressor which replaces the ours is called SD5H14, and does NOT turn in the correct direction.

I never heard that. Mine was always charged by evacuating the system to a certain negative pressure for a about 30 mins (to verify it's not leaking) and then the R134a gets sucked in by the vacuum. Engine definitely not running during the process.

 

And the QV. The 8 has a slightly different HVAC system, betweeb the Dino GT4 and the QV.

 

I never heard anything like it and I do it every day several times without any issues - could you show where this is written?