[MidLifeZ]

1994 S4

No AC... thoughts?

Hadnt had need for AC since install of new stereo until the other day, turned fan on, spun AC temp control and nada...

Compressor does not turn on
Fans to radiators do not turn on

Pulled head unit to see if connected something wrong after removing the HVAC controls during install of the double DIN stereo and only things I can figure are:

A. the wires to the fan control, there are 4-5 of them, were connected wrong. Specifically would have to be I think the ones toward botton where there are three of them. Anyone have clues on which colored wires go where on the fan?

B. see pic below, cannot find anything this would connect to. Maybe not used??

Checked all fuses front and back (boot and bonnet) though did not have a way to check the relays in the boot...

Suggestions?

 

[MidLifeZ]

No cold air suggestions?

 

[mpesik]

No cold air suggestions?

Hi.
Cant help you but I am watching this Thread to perhaps sort out my AC problems.
Luck.
Mike.

 

[jtrealty]

The single most common cause of no A/C is low refrigerant because of a leak. Check your low side pressure. If it is below 60 psi the low pressure switch is keeping the system from working. The quick fix is to add some refrigerant. The "right" way to fix it is to find the leak, remove the refrigerant, fix the leak, and then refill with the proper quantity of refrigerant.
David Teitelbaum

 

[delomike1049]

Very first question - Have you put gauges on the A/C system yet?

 

[MidLifeZ]

To answer, no I have not had gauges put on the AC system as yet... Will give that a shot today as long as can locate just a way to test pressure, i.e. gauge to test myself

So I understand the replies:

1. Are you saying that if the refrigerant is below a certain level it is detected and the system will not allow for the AC compressor or radiator fans along with it to turn on?

2. If the either the refrigerant is not low or if it being low does not trigger so the AC compressor and radiator fans kick on, what else suggest to look into?

3. Anyone know what the connector in the photo I uploaded is supposed to plug into if anything?

4. Can anyone provide info on which color wires go to which spade connectors on the fan control?

There are five connection points on the back of the fan control knob arranged as thus:

1 2

3 4 5

I might add that while it had been quite some time since had any need for AC (2-3 months?) it worked fine then. I have since that time of course done the Double DIN install which still leads me to believe something amiss in the HVAC controls area in the cockpit..

 

[MidLifeZ]

Boy do I feel stupid...

Go to check sight glass in the bonnet for AC level ...

Take a guess....

Yup, one of the two wires not connected

Sheesh, took stereo out and all sorts if stuff with no need

 

[Turbo R]

I know that feeling really well!
We've allllll been there.

Happy to hear you found the source of your problems, Kenny!

Happy Saturday, all!!!

Roy

 

[MidLifeZ]

OK, one more thing..

Got stereo put back in, etc., etc.

When turn the fan knob and with AC control knob full clockwise, when turn fan knob to first click (lowest speed) the AC compressor clicks on and the radiator fans can be heard turning on. BUT if turn fan speed up any higher than the first click I can hear the AC compressor click off and the radiator fans turn off.

This is all while sitting still in garage...

I am still concerned that the three wires connected to fan control nob at bottom are not plugged in to their correct spots on the fan speed control knob and this is causing this oddity.

Thoughts?