please help i only have air blowing out of the defrost vents!!!! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

eliminator024 · 07-06-2011, 08:37 PM

i have a 1990 Nissan 240sx it only blows air out of defrost no where else and i cant stand this California summer heat lol, can someone please help me out on how to fix the problem. Also the light to the a/c button does not come on i dont know if it works or not or has anything to do with the problem.

jesse_s13 · 07-06-2011, 08:40 PM

Have you checked to see if the ac compressor turns on?

lazysk8er2 · 07-06-2011, 08:42 PM

check the fuses!

AutechKouki · 07-06-2011, 09:28 PM

Defrost vent might be air vent servo motor being out, and your compressor not turning on is most likely low refrigerant charge or no refrigerant at all.

eliminator024 · 07-07-2011, 02:29 AM

Its not the fuses or the compressor its something else causing it to only blow from the defrost vents, checked the fuses there fine. I was using the heater last year and all of the sudden it only blew through the defrost only so idk what broke.

mad-ass · 07-07-2011, 03:11 AM

your hvac unit maybe dead is no longer telling the vent arms to move to correction position when position selector is pressed.

eliminator024 · 07-09-2011, 07:35 PM

So I need a new control unit the conrtol part by my radio and it should work??

mushmonster · 07-10-2011, 03:17 PM

With a test light check power at the mode door servo (driver side-right of gas pedal) when actuating each mode if no power, may be control head or power from 10A fuse at drivers side kick panel. No ac light may mean issue at the relay(drivers side engine comp fuse block), wiring, or control head. check for power at ac clutch on compressor.

jaked23 · 07-13-2011, 10:02 AM

the air ven doors are ran by vacuum. you probably have a vacuum leak somewhere. when there is a vacuum leak, it defaults to defrost

eliminator024 · 07-20-2011, 12:26 AM

Where are the vacuum lines under the dash?

07-06-2011, 08:37 PM	#1
eliminator024 Join Date: May 2010 Location: riverside Age: 29 Posts: 37 Trader Rating: (1) Feedback Score: 1 reviews	please help i only have air blowing out of the defrost vents!!!! i have a 1990 Nissan 240sx it only blows air out of defrost no where else and i cant stand this California summer heat lol, can someone please help me out on how to fix the problem. Also the light to the a/c button does not come on i dont know if it works or not or has anything to do with the problem.

07-06-2011, 08:40 PM	#2
jesse_s13 Nissanaholic! Join Date: Aug 2010 Location: Sacramento,CA/Fresno,CA/El Paso,Tx Posts: 1,829 Trader Rating: (5) Feedback Score: 5 reviews	Have you checked to see if the ac compressor turns on? __________________

07-07-2011, 03:11 AM	#6
mad-ass Nissanaholic! Join Date: Jun 2007 Location: Nor Cal Posts: 2,273 Trader Rating: (14) Feedback Score: 14 reviews	your hvac unit maybe dead is no longer telling the vent arms to move to correction position when position selector is pressed. __________________

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07-06-2011, 09:28 PM	#4
AutechKouki Zilvia Addict Join Date: Jan 2011 Location: SoCal Age: 29 Posts: 669 Trader Rating: (43) Feedback Score: 43 reviews	Defrost vent might be air vent servo motor being out, and your compressor not turning on is most likely low refrigerant charge or no refrigerant at all.

07-07-2011, 02:29 AM	#5
eliminator024 Join Date: May 2010 Location: riverside Age: 29 Posts: 37 Trader Rating: (1) Feedback Score: 1 reviews	Its not the fuses or the compressor its something else causing it to only blow from the defrost vents, checked the fuses there fine. I was using the heater last year and all of the sudden it only blew through the defrost only so idk what broke.

07-09-2011, 07:35 PM	#7
eliminator024 Join Date: May 2010 Location: riverside Age: 29 Posts: 37 Trader Rating: (1) Feedback Score: 1 reviews	So I need a new control unit the conrtol part by my radio and it should work??

07-10-2011, 03:17 PM	#8
mushmonster Leaky Injector Join Date: Jun 2010 Location: PalmCoast, FL Posts: 52 Trader Rating: (4) Feedback Score: 4 reviews	With a test light check power at the mode door servo (driver side-right of gas pedal) when actuating each mode if no power, may be control head or power from 10A fuse at drivers side kick panel. No ac light may mean issue at the relay(drivers side engine comp fuse block), wiring, or control head. check for power at ac clutch on compressor.

07-13-2011, 10:02 AM	#9
jaked23 Join Date: Apr 2011 Location: st louis Age: 30 Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	the air ven doors are ran by vacuum. you probably have a vacuum leak somewhere. when there is a vacuum leak, it defaults to defrost

07-20-2011, 12:26 AM	#10
eliminator024 Join Date: May 2010 Location: riverside Age: 29 Posts: 37 Trader Rating: (1) Feedback Score: 1 reviews	Where are the vacuum lines under the dash?