Air conditioning question for 1991 Testarossa

1. may be one of the airhoses are broken somewhere or disconnected and the air is passing there? but the normal airflow is not so like from a hairdryer

2. you may take out all the freon (134A ) gas. I´m sure you get out only about max. 25 % of this what has to go in. then refill and it will blow cold again also in idle.

 

If you still have the R-12 freon ? If you are able to source R-12 freon, use it. Don't switch to R-134 unless last resort. You may have moisture in system. Evacuate (pull vacuum) save R-12, change drier.


Ago

 

The air tubes going from the main center plenum chamber to the side vents aren't huge, and they have some sharp bends IIRC so not great when even working as designed as romano indicated. However, they are double-walled insulated tubes, so if your dash has been disassembled/reassembled, it's easy for the reassembler to do this wrong and get the outermost tube wall onto the fitting (so it looks right) but the innermost tube wall (that actually conveys the air) is folded/crunched up/blocked. Has you dash ever been disassembled/reassembled? (But I wouldn't do anything here until looking at the things in #2 below.)

This can be a symptom that the AC condensor fan mounted forward of the LH front wheel isn't operating. On a hot day with the coachwork stationary and the AC "on", stick your hand in front of the LH front wheel = hot air should be blowing out. If not = something electrical not right (motor rotten, fuse-relay board connection burned, fuse blown, bad AC condensor fan relay, bad thermal switch on high pressure line, etc.). Also, you may have a lot of debris blocking the AC condensor radiator core (the inlet is the single vent in the LH side of the front spoiler).

If the AC condensor fan is working and the AC condensor radiator is clear, the other easy thing to do is to just look at the refrigerant observation window on the AC dryer -- good = a moving liquid stream; not good = moving liquid stream with bubbles; bad = no movement.

 

Just adding to the expert knowledge above....

When investigating a RPM gauge issue, I pulled the cluster. Guess what? The left tube going to the left circle dash vent was un-hooked. Everything was there, just not connected. Life goes on after re connecting.

 

with a leak detector you normaly will find every leak in the AC system.
I put sometimes special color ( light green ) in and after about 2 weeks if it is leaking only a little I see where this color comes out.
so before removing things first check where the leak is

 

I can not get compressor to turn on. I assume the dial on the console just needs to be turned to cold, but nothing happens. The push buttons do not do much either. Any suggestions? Unless I am missing a button I am supposed to push. Thoughts?

 

Please clarify your symptom -- are you saying:

1. The interior air blower fan does not come "on", even when set to max speed, or

2. The interior air blower does come "on", but the AC compressor clutch does not engage?

For 1, the prime suspect is a frazzled/burned connection in the k horizontal white connector at the bottom of the fuse-relay panel.

For 2, most likely the high/low pressure switch on the dryer is not closed (because the refrigerant has been lost).

 

Sorry the blower is fine. The AC compressor will not come on, or I don't know how to engage it. I assume I just turn the temp dial down to cold setting?

 

What pushbuttons have you selected on your centre console (next to the gearstick)?

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Button 13 = STOP button
Button 14 = climatised air
Button 15 = ventilation air
Button 16 = maximum windscreen demisting

 

Yes, that's the correct operational procedure for the User to get cooling (and have the AC Compressor engage), but it also requires that the high/low pressure switch at the dryer to be closed (i.e., it requires there is enough refrigerant in the system). Use a jumper wire to connect the two terminals at the high/low pressure switch (simulating a closed high/low pressure switch) to see if that gets the compressor to engage, or not. If it does engage with the jumper in place = either no refrigerant or bad high/low pressure switch (and looking at the sight glass window on the dryer with the compressor engaged should let you confirm/deny if any refrigerant is flowing). If it doesn't engage with the jumper in place = some other electrical Gremlin, bad input sensor, or a bad AC ECU. Do you have a copy of the TR WSM for the input sensor tests shown in Section H (IIRC)?

PS When you say: "The AC compressor will not come on" -- do you just mean that you don't get cold air to come out, or are you actually measuring something at the AC compressor EM clutch?

 

Great info. Actually I am using my ears and other senses to confirm the AC is not working also the seller told me it wasn’t. I have turned the dial all the way cold but was wondering if a certain button needed to be engaged.. Pretty sure you don’t.. I certainly agree the issue is probably a leak that triggered the pressure switch. Always follow the bread crumbs.. I’ll give it a jump and see what we can rule out. Tks

 

Pretty munched pressed them all I believe.