1998 Nissan Quest • 140,000 miles

The AC control, [ its automatic] stopped working, display wont come on, and the unit blows HOT air only, replaced the control unit with same style, and still no a/c. Jumped the blue pressure switch out compressor does kick in, but accumulator stays warm and still no cold air. Any ideas, would help thanks.
May 28, 2012.

You really neeed t have apro look at this to see if there is any freon in the system. Especially if you jumped the pressure switch and nothing happened.

May 28, 2012.
Really? If you cared to read my question I'm lacking proper operation of the automatic air controller, maybe my knowledge of jumping out pressure switch should indicate my ability to test for freon, I'm asking about the controller part of the operation.

May 29, 2012.
Ok first you have to check for power and ground, if it has those it's replace the unit. For it to self idagnose, start engine, push offf and mode switch at same time see if codes come up.

Code No. Go To Diagnostic Procedure No. Sensor Or Circuit
10 (1) 13 Rear Air Mix Door Shorted
12 13 Rear Air Mix Door Shorted
16 14 Rear Air Mix Door PBR Circuit Shorted
17 14 Rear Air Mix Door PBR Circuit Open Or Voltage Too High
18 13 Rear Air Mix Door Time Out
20 (1) 4 Front Air Mix Door Shorted
22 4 Front Air Mix Door Shorted
26 5 Front Air Mix Door PBR Circuit Shorted
27 5 Front Air Mix Door PBR Circuit Open Or Voltage Too High
28 4 Front Air Mix Door Time Out
30 2 In Vehicle Temperature Sensor Shorted
31 2 In Vehicle Temperature Sensor Open
40 1 Ambient Temperature Sensor Shorted
41 1 Ambient Temperature Sensor Open
42 (1) 1 Ambient Temperature Sensor Shorted
43 (1) 1 Ambient Temperature Sensor Open
50 3 Sunload Sensor Shorted
52 (1) 3 Sunload Sensor Shorted
60 (1) 18 Mode Switch Button Stuck
61 (1) (2) Ignition Over Voltage
80 (1) 7 Front Intake Door Shorted
82 7 Front Intake Door Shorted
86 8 Front Intake Door PBR Circuit Open Or Voltage Too High
87 8 Front Intake Door PBR Circuit Shorted
88 7 Front Intake Door Time Out
90 (1) 6 Mode Door Shorted
92 6 Mode Door Shorted
98 6 Mode Door Time Out
(1) Indicates intermittent fault.
(2) Check charging system.
Have fun

May 29, 2012.
Trying to locate a wiring diagram of the ac control unit on this van, ive already replaced the control unit, and power is present, but im not sure where power has to be present at on the terminal blocks, I havent checked for ground yet, thats my next step, a, diagram sure would be helpful, thanks.

May 29, 2012.
If you didn't get cold air when jumping out the switch, then you have more issues than just compressor power. Take hmac300's advice and pay a professional. You really are over your head here.

May 29, 2012.
Pin 23 -gray pin 32-ppl are power pin 30-blk ground and grounds to left kick panel. Happy hunting

May 29, 2012.
I jsut got an updated schematic chec fuse C at teh underhood fuse box fusible link box.

May 29, 2012.
Hey appreciate the info very much, I just got ahold of the wiring diagrams thru AllData, , which is what I needed, as for being over my head, nothing like a challenge, mite Not be a pro but, perseverance, common sense and basic knowledge are a driving force. Thanks guys.

May 30, 2012.