Have you checked your fuses? You could have an electrical issue also. If the fuses are good, you need to check your wiring harness for these parts.

Please see my tip at http://www.fixya.com/cars/r6235876-no_heat_fan_blowing_cold_air . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

If the blower works on lower speeds then its likely the fuse or wiring or relay. Attached is an 2001 Impala Diagram, couldn't find the Monte online. I assume they are similar.If the relay doesn't pull the switch to the other side then you would never get full speed. (Full speed does not go through resistors normally) If you go to a Library they will let you copy their Chilton's Ref Books for like 25 cents per page. But call first and make sure they have Chilton's or similar book.

That is your a/c compressor kicking on and off to create air to the defrost. The a/c compressor will only kick on when the a/c is on or the defrost.

They are vacuum controlled. Have you checked the vac lines on the engine? What engine do you have in your Monte?

my heater in car 2003 chev monto carlo v6 is not getting hot?

could be ur selector switch or heater control mod

check freon level

It may be an intake leak. Oil maybe leaking into the radiator. You need to replace the intake gasket.

i suggest that you **** **** and choke on it *****