360 poor heat and A/C

Connect a diagnostic computer to the system to see what the temperature inputs and outputs from the control unit are.

 

So does it or doesn't it blow cold/hot air? if you can scan it.. go for it as above.

My bet would be on the control unit going. Mine suddenly didn't blow ac. Turns out Control Module was bad. Getting more common as these cars age.

 

It may be the TGK Valve Part # 65066400, it is located under the removable access panel under the hood. My mechanic said this is a common problem with the hot/cold air not reaching the desired temp inside the cabin.

 

How long have you owned this car ? I thought I had a problem with my heat also until I read that the stop button needs to pushed in for the heat to work. After I pushed the stop button in I had heat! Hope your problem is solved this easy.


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On my car, it's the other way around. The stop button has to be out for the heat and A/C to work.

 

+1

After 7 years I still sometimes get it backwards!

 

You are correct , took the car out today and realized it has to be out for heat to work . Very confusing ...

 

Don't. My first Ferrari I didn't know that either. The only time I push it in is for track days.

 

My A/C stopped blowing cold last summer. It was working fine the previous summer.

Yesterday:
I had the seat out and decided to give a look and see what could be seen. The clutch definitely engages with the "STOP" button out (not illuminated). With the car running, I decided to check the add fluid port, and it looks like pressure could be high running max fan, Lo temp (also no can was attached). NO cold air coming out and it's only 65F here.

Today:

• Warmed the car up to operating temperature.
• Started at LO - STOP illuminated and increased until HI - NO heat! (owners manual states heat should work)
• Disengaged STOP - A/C compressor started and heat came on at HI!
• Gradually decreased temp until heat went away - NO A/C!
• I basically tried all the settings:
  • Heat only works when STOP not illuminated
  • A/C compressor runs 100% of the time when STOP not illuminated
  • NO cold air at the vents!

Hoping someone knows what's wrong or has some ideas to try?

Operating temp:
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Pressure at port - no can attached.
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Ended here - NO compressor , NO heat!
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Compressor started + heat came.
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Gradually decreased temperature until LO - compressor running, NO A/C!

 

I had mine rebuilt, and it was fine for a few months as well.

 

There are too many people who say the heat only works when the STOP button is not illuminated ("released"). The owner's manual and the WSM may be wrong for the 360.

WSM:

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My F355 also provides no heat with the STOP button pushed. Un-pushed, the heat comes on in seconds (after the car is warmed up)

 

I thought I tried every option... I will go check again, but I don't recall the re-circulation button "lighting".

 

Yeah, I think it's just an error in the manual. Looks like they cut and paste the text incorrectly

 

I did see a table on FChat showing symptoms vs what could be wrong.

Is the fill port the low side of the gas system on a 360? Maybe you need to check the pressure on the high side.

 

It looks like not knowing the high pressure side is worthless!

I borrowed a set of A/C gages from a friend. Car sat for a week. Low side = high side.
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Car running with max A/C on LO.
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It appears all I need to do is add fluid! But you can't tell from just the low side pressure gage which seemed to be a little on the high side. The low side gage indicates air temp shouldn't be any cooler than our current ambient!

I will wait a few days until it warms up enough to feel the colder air...

 

What happens when you heat up the cabin first, then switch to cold. I'm guessing (no expert here), there should be a greater demand on the AC system (shown on the gauges) which I assume will be shown by a greater high/low differential pressure.

 

Oh boy. I added more freon and that didn't help at all!

After starting up with A/C full blast on LO. Essentially ambient temp.
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Added freon both high and low pressure increased. Note: the temp scale on the low side is approaching 70F and 70psi!
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Disconnecting the high pressure line, this was bubbling out! Very oily and cold! I am guessing that is NOT normal?
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And as the gages indicated, the temp would be higher! Near 70F from the A/C. This is above ambient.
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Does this mean I have a "weak" compressor? AND/or expansion valve problem? Obviously not an easy fix from here.

 

For reference, the WSM says 196psi high side/29psi low side after several minutes of running, but it does depend on the gas and the ambient temperatures.

I'm probaby teaching granny to suck eggs, but you have to add the refrigerant by weight after evacuating the system, not keep pumping new refrigerant into the system.

I'm sure there will be an expert along shortly, but how fast do the pressures (roughly) equalise after you turn off the AC? I believe this is a way of distinguishing between a weak compressor and a faulty expansion valve (i.e a valve which is not restricting the flow enough). A fast drop means the expansion valve is not working properly. Don't know what the time frame is, though.