air/heat is only coming from the defog vent, why??!!
Thread Starter
Member
Joined: Sep 2004
Posts: 192
Likes: 0
From: Albuquerque / Las Cruces, New Mexico
Car: 91 camaro z28
Engine: 6.3L, heads, headers, cam,.....
Transmission: 700-R4 w/shift kit and 3-4 WOT kit
Axle/Gears: 4.11
air/heat is only coming from the defog vent, why??!!
I dont really know were to post this question!
Ok you guys I got a question for you all. Well when I turn on the heater or air, air only comes from the dash vents (for defogging) but only when the lever is switched to defog. And when I switch the position of the air it continues to blow (I can hear it) but air is not coming out from any vent. Does anyone know why this is happening? All this is from memory, I haven’t driven it since the motor been out (go figure!) and it been over a year. But things are slowly coming together and wouldn’t mind trying to find out the problem before the car starts running again so I can have a heater!! I would really appreciate your help, Thanks!
Ok you guys I got a question for you all. Well when I turn on the heater or air, air only comes from the dash vents (for defogging) but only when the lever is switched to defog. And when I switch the position of the air it continues to blow (I can hear it) but air is not coming out from any vent. Does anyone know why this is happening? All this is from memory, I haven’t driven it since the motor been out (go figure!) and it been over a year. But things are slowly coming together and wouldn’t mind trying to find out the problem before the car starts running again so I can have a heater!! I would really appreciate your help, Thanks!
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Joined: Feb 2005
Posts: 2,509
Likes: 201
From: Hawaii
Car: 89' Firebird / 87' Formula
Engine: 3.4 / 5.0
Transmission: 700-R4
Axle/Gears: 3.42 / 3.42
well, the a/c vents run off of vacuum.....and without a motor, you ain't got no vacuum
Defrost if the default sertting when you hsve no vacuum
Defrost if the default sertting when you hsve no vacuum
You said from memory so I suppose this was before engine was removed. The problem is probably in the control switch. Mine would only blow ac and defrost. Vent and heat went to defrost, ac compressor was not activated in vent or heat. I replaced the switch assembly and all is well. I opened up the tan colored switch and did not find what I expected, I can feel the lack of detent when it moves across vent and heater but I can see no damage or reason for it not to function. I plan to put my mulitmeter on it over the weekend and see if I can find the problem, repair and have a spare.
I took a look at local salvage yards and all the switch assemblies were gone and I just happened onto the one I installed last week.
I took a look at local salvage yards and all the switch assemblies were gone and I just happened onto the one I installed last week.
Supreme Member




Joined: Feb 2005
Posts: 2,509
Likes: 201
From: Hawaii
Car: 89' Firebird / 87' Formula
Engine: 3.4 / 5.0
Transmission: 700-R4
Axle/Gears: 3.42 / 3.42
oooohhh.....it's from memory!
You may want to check out the vacuum lines in the engine then. I believe there was a topic in the V-6 section regarding this exact same problem and it turned out to be a bad vacuum hose. Allo, check the ball thing that hold vacuum on (I think) the drivers side.
You may want to check out the vacuum lines in the engine then. I believe there was a topic in the V-6 section regarding this exact same problem and it turned out to be a bad vacuum hose. Allo, check the ball thing that hold vacuum on (I think) the drivers side. Thread Starter
Member
Joined: Sep 2004
Posts: 192
Likes: 0
From: Albuquerque / Las Cruces, New Mexico
Car: 91 camaro z28
Engine: 6.3L, heads, headers, cam,.....
Transmission: 700-R4 w/shift kit and 3-4 WOT kit
Axle/Gears: 4.11
Thanks for the input guys! Well I just look over the vacuum lines for now and then Ill go from there once the motor is back in!! Thanks a lot for the help
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