I have a 2004 Nissan Maxima GL and when I turn on the air for either heat or AC I do not get any air at all. Please help.

check for a stuck open coolant valve to the heater core. check for an air flap that is stuck open too . thanks.

Turn the ac switch to the off position it will still blow air the fan runs on low all the time if the ac are heat is on.

Well thinking about the problem there e a flap in the vent pipes to shut off theatre and ac unit perhaps something has got in the pipe and stopping it closing or perhaps your heater control is US and needs replaceing . ( but I take it you have turned your heater to cold )

check ac fuse and power to blower under glove box

It sounds like a burned out circuit on the ac compressor clutch while the car is NOT running grab the ac clutch assy on the front face of your ac compressor it should turn with very little drag if it is seized it wont turn at all causing your problem the wires short out and when you turn on ac you get nothing

If the engine is heating properly you most likeliy have a clogged heating coil or regulator (opens to allow hot water to flow thru the heater core. No hot water to the heater cord, not heat in the vehicle. Good luck

air trapped in system. get flush & fill from shop with evac/fill equipment

I have a 2002 nissan Maxima. The AC controls only blow on level 4. No air or heat blows from level 1-3. What do I need to do to repair this problem?

you possibly need a thermostat or even a water pump you can fill up the coolant at the radiator cap..its a silver cap near the front ov the car you need to push down on it and turn counter clockwise

the a/c condenser has a fan in front ( there is actually 2 fans if you sit on the car it will be fan on right side ) if this fan does not
come on immediately when you are parked and engine in idle
there is a problem with power to it, or motor failure. If you drive it
on the highway and a/c operates fine that's because air is circulating though condenser (thats what the fan is supposed to do at idle or slow traffic)