Best Answer

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

User Avatar

Wiki User

โˆ™ 2015-07-17 17:42:52
This answer is:
User Avatar

Add your answer:

Earn +5 pts
Q: Why does the heater in the rear of a 96 Chevy Astro van blow cold air and in the front of vehicle blow hot only when the defroster is switched on?
Write your answer...

Related Questions

Heater sensor circuit Chevy Astro 2000?

heater sensor circuit Chevy astro 2000

How do you install a heater core on a 1994 Chevy astro 4.3 liter van?

How do you change a heater core in 1994 chevy astro van?

How to change Chevy astro?

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.

Where is the heater resistor located on a 1994 Chevy Astro?

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.

Where is the block heater cord located on a 2001 Chevy astro van?

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.

Change heater core in 1998 Chevy Astro van?

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 do you remove heatercore 87 astro van?

how to remove heater core 87 Chevy astro van. like to have diagram.

Why does 1994 astro van Air conditioning blows through defroster vent?

small vacuum hose in engine compartment is cracked

Backflushing heater core on 1986 astro?

If that made sense i'd answer it

How do you change a heater blower motor on a 2000 astro cargo?

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.

Where is the heater core on a 1998 astro van?

On the passenger side in the black box

How do you fix the heater in a 1994 Chevy Astro Van?

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.

Can not get the fan to blow on hi on a 2001 Chevy Astro van?

get a new heater switch

2002 Astro heater doesn't work on high speed?

you might need a new switch.

Location of heater fuse for 96 astro van?

40 a or 40 b fuse i think

How can you chance the starter in your Chevy Astro 99?

The Starter is accessible from beneath the vehicle

Where is the heater core located on a 1989 Chevy Astro Van?

It should be located at the passenger side under the instrument panel area next to the heater control box

Why does a 1987 Astro van have no heat and blows cold air out vents?

It's either the thermostat or the heater controls.

What would cause smoke to come out of heater ac control box on 94 Chev Astro Van?

A Fire!

Where is the stock block heater cord on a 1997 Chevrolet Astro?

it will be on the driver's side underneath the hood behind the headlight.

Why does the horn on a 1990 Chevy Astro work only when the vehicle is turned off?

Is it possible that the wiring to the horn relay or switch have been switched around? Possibly a misconnection in the ignition switch itself causing a faulty circiut similar to a short? Just a couple of ideas I thought of. ------- It is probable that you have a

Where is the fuel filter on a 1994 Chevrolet Astro?

Under the vehicle, about halfway back on the drivers side.

Where do you get your learners license in lethbridge Alberta?

You can get it either at astro insurance or lethbridge vehicle license and registry.

Where is the abs relay located on a Chevy 2002 astro van?

There is no ABS relay on a Chevy 2002 Astro Van. If the ABS light is on it is indicating a problem with the vehicle that should be checked out.

How do you change the dashboard rear wiper and heater lights on a 2002 Astro van?

I dont think you can. I believe they are part of the switch