Not much info to go with. Need to know if the blower motor operates or not.
Yes it will stop heating up...........
There could be multiple reasons why a heater would stop working in a truck. There could be low coolant or a bad fuse to make a heater stop working in a truck. The best way to find out the reason is to take it to a certified auto mechanic.
heater core
The heater on a Mercedes c200 will stop working if the heater core is blocked. It allows hot coolant from the engine to be used in heating the cabin.
If you have lost a sufficient amount of coolant this will stop the heater working because there will be no hot water in the heater rad.
you need to replace your heater core.
There are a couple of reasons why a 1999 Oldsmobile Alero ac heater to stop working. The heater coil may need to be replaced or the HVAC blower motor may need to be replaced.
YesYes
Could be low on freon,
yes
It could be that you A/C is running low on fluid.
The air conditioner may have stopped working in a 2001 Acura TL because it needs Freon. It may also be a problem with a connection somewhere.