Probably programmer, It needs to be checked out.
I had the same problem....the easiest way to know is to safely jack the vehicle up, run it until it's hot then follow the rubber coolant hose from rear heater to the engine. You will likely find it is cold all the way to the front. If you remove the fan shroud etc you will see a coolant distribution valve ( there are two) plastic and avialbale from GM. They have vacum connections on them. Check to be sure the connections are ok. If so the valve is likely stuck in the closed position prohibiting any coolant flow to the rear heater from the engine cooling system. The valve ( I would replace both while there since they are buggers to get at and change) . jk
heater sensor circuit Chevy astro 2000
How do you change a heater core in 1994 chevy astro van?
A) Drive to dealership. Select new vehicle. Trade your Astro for new vehicle. B) Push Astro off a cliff. Walk to dealership and get a new vehicle.
The heater resistor on a 94 Astro is located on the top of the heater box under the hood, it has a four or five wire plug on it and two 6mm screws hold it in a hole in the heater blower box.
You can find the block heater cord behind the grill of your 2001 Chevy Astro. The cord will be on the drivers side of the grill.
Drain the water from your 1998 Chevy Astro cooling system. Remove the water supply hoses from the heater core. Remove the heater core retaining bolts. Reverse the process to install the new heater core.
how to remove heater core 87 Chevy astro van. like to have diagram.
If that made sense i'd answer it
small vacuum hose in engine compartment is cracked
On the passenger side in the black box
To change the heater blower motor on a 2000 Chevrolet Astro Van open your hood. After you open the hood you will see the heater box on he passenger side remove the four bolts holding the motor in and pull it out.
I have a 1996 Astro van and I'm having trouble too. My fan motor sticks. It has for a while. Its not the heater but the fan that has draged. I can get out and pound on the casing, and sometimes it starts up.