The problem may be a stuck valve which switches between A/C, heater, and defrost vents. My car is stuck in defrost, and is suffering a vacuum leak that is also impacting the idle speed. I was looking for the vacuum diagrams as I found this thread. Good Luck.
I had the hot air problem and recently replaced all the smallest vacuum lines (about 1/8") under the hood. There is one vacuum line from the vacuum reservoir that goes through the firewall. I removed the glove box and while lying on my back, head forward, could reach the "t" connection. I removed that hose end and used a machine screw with the head cut off to attach new hose. I attached the other end of a sufficient length of new 1/8" hose to the "t" and had a helper pull the vacuum line into the engine compartment while I fed the remainder. Re-connected to the vacuum reservoir and all works well.
Dude, this is a VERY common problem in all Z's. The easiest fix is to disco/bypass the the heater core (in the summer) and hook it back during the winter months. Good luck.
People are not being very helpful here. There are two major causes to this specific problem.
1) There are three vacuum lines between the intake manifold and the climate control system: First, a supply line that runs from a vacuum outlet at the right rear of the intake manifold to a vacuum canister just behind the right headlight. Second, a switched vacuum line from the canister to the hot water valve on the firewall. And, Third, a vacuum supply line from the canister to the climate control system behind the dash. All three of these lines get brittle and crack/break from age, causing leaks. Since the hot water valve requires vacuum to turn OFF the hot water, any loss of vacuum leaves the hot water ON all the time. If you haven't done it, its always a good idea to replace these three vacuum lines with new hose. For the line to the interior, just cut it off with 6-12in of slack and connect a new line to it with a plastic vacuum coupler. This will fix the hot air problem, even though there may be other climate control problems.
2) The Z31 Climate Control system uses three vacuum servos to control air doors [which controls air flows in different modes]. These vacuum servos use large rubber diaphrams that also go bad over time and fail, leaving the servo inoperative. One of these servos is behind the glove box and controls intake air and can be replaced easily. But the other two servos are behind the climate control air box, up against the inside of the firewall. Replacing them requires a complete tear-out of the seats, steering wheel, console, and dashboard. This is not a job for the faint at heart. I've done it now on two '86 300ZXs and had perfect climate control operation ever since.
It could also be a faulty heater core, check to see if you are leaking any from the passenger side, it could also be the vacums, i sugest you don't do it yourself as in fix it inless you deffintly know what your doing, the instructions people give you arnt always the best to go by, i have replaced my heater core in my 85 but it turned out to be alot more then what the instructions originaly said, so don't do it inless your sure you can, because there is alot of eletrical and parts under there.
You have to first diagnose and correctly identify the issue causing the problem before you can repair it. There are several reasons why AC systems can blow hot - to know how to repair it you need to know that reason.
it is a vacuum leak-replace the vacuum line from the right side along the right front-tiny vacuum line probably split
you have to by pass the heater core. get a 3/4 heater connection piece just one way trim your hoses down and then plug off your heater coe connections on your fie wall might try to take out fuse for blower motor if that dont work.you have to bypass heater core very simple thing
TRANSMISSION MODULATOR SEE IF IT BLOWS SMOKE OUT THE EXHAUST
May need a refrigerant charge Buy a kit at Wal-Mart or auto parts comes with instructions
Possibly needs recharged with refrigerant. You can check low pressure side with a guage.
the heater blows warm air when fan is on low but blows cold air when fan is turn to higher setting
A shorted wire in the console or the brake circuit. Does the car still have brake lights? If there are no children in your household then it is possible to defeat the lockmechanically.
where do I start? help? it is getting close to the cold season and I would like to repair my house before the wind blows.
I have a 2006 Altima and it is doing the same thing.
AnswerReplace the blower resistor.
that is bad... go get it checked up on!
check you thermostat for the temp setting
Two problems that I can think of are you need to add some antifreeze or you need to replace the thermostat. Two problems that I can think of are you need to add some antifreeze or you need to replace the thermostat. Two problems that I can think of are you need to add some antifreeze or you need to replace the thermostat.
MY 05 NISSAN MAXIMA BLOWS HOT AIR. WHEN THE CAR HAD 15000 MILES WE TOOK IT TO THE DEALER FOR THE SAME PROBLEM AND THEY SID THE COOLANT WAS A LITTLE LOW AND THEY ADDE SOME. BUT THE PROBLEM HAS PERSISTED AND NOW WE HAVE TO TAKE IT BACK AGAIN. THE CAR NOW HAS 22000 MILES.
it could be your fan motor is going to go
It sounds like your air flow diverter is stuck on defrost. Basically it is a little door that diverts the air fom vent to defrost to feet. It could be either the heater control valve, or te temperature selecter cable is broke.
To repair the Reatta running lights check the fuse first. If the fuse is blown ad a replacement blows then check the lights and wiring for any shorts.
TRY THE AIRCONDITIONING BELT
Your compresser blew. Common problem with this vehicle. Expensive to repair. Your compresser blew. Common problem with this vehicle. Expensive to repair.
An automobile's heater that blows only cold air could either be a faulty thermostat or, more likely, a faulty heater core. A trip to a mechanic or shop that specializes in radiator and cooling system repair should be able to diagnose and repair any problems.
Sounds like it needs a new thermostat.
refill the a/c, it will blow hot air with no refrigerant in the vehicle.
Blows on #4 only? I would replace the resistor. #4 speed by-passes the resistor.
google astrosafari van repair and you will find a lot of info on how to repair/replace your vacuum lines and valves