Blowing cold air no heat

You probably have an air bubble and therefore doesn't have enough anti freeze in the system. Carefully remove the radiator cap when the engine is running and verify it and/or notice the hot/cold marking on the overflow tank. The system needs to be full to heat.

So it blows in the front and the rear ok. Where else do you want it to blow?

I have a 2000 pontiac grand prix with a digital climate control system. The heat quit working, it doesn't blow out any heat. Now that it is warm outside the air stopped blowing out any air. The digital temperature on the climate control is not correct. When it states that it is below 30 degrees on the ext and it is warm outside the air wont be cold. Once it starts going above 30 degrees the air gets colder. Today the blower stop working all together. Was told it maybe the climate control unit was bad. You can hear the door opening/shutting when you switch the temp from cold to hot. But there was no heat blowing out whatsoever in the winter time. Could you please give me your opinion on whether or not it is the climate control unit or something else?

it sounds like the heater core is stopped up and the hot air can not blow thru

I had the problem with my 2004 9-3. It turns out that there is a motor that opens a door to let in the hot air from the engine. I had to get this changed at a dealer--an independent repair shop could not do it. Parts and labor totaled $365, including tax, done in January 2011 in Orange County, CA. Good luck.

When I turn on the heat in my 2004 mazda mpv the front air vents blow heat but the rear air vents are blowing cold. I have adjusted every setting is there something I am overlooking.

2004 mercury mountaineer.heat problem
When turning ac knob to heat clicking sound like door opening and closing repeatedly sounds and air blows cold instead of hot.

check and fill radiator and filler canister for coolant.

Warm up vehicle, then access heater pipes that run to rear of vehicle.  they should be HOT. if not you have  a circulation issue.  IF they are hot, then the blend door is not in the correct position.  this door directs air across a hot or cold core to create the correct air temp. check and update me.  

There is a mix damper inside your duct that controls the heat over heater core and ac evaporator that to your floor and one to your defrost. it is probable an electric actuator, that is not functioning properly. If yu can locate it and manually move it, you might have to remove the actuator motor first, you should be able to figure out your problem, I hope this helps! merry Christmas!