1999 chevy venture only blowing cold air at rear

I couldn't find a heater hose diagram specific to the 1999 Chevrolet Venture with rear heat and air, but I can give you the general location of the heater hoses and how to identify which ones go to the rear heat. The heater hoses on a 1999 Chevy Venture are located on the passenger side of the engine compartment. There are two heater hoses, one that is hot and one that is cold. The hot heater hose will be connected to the heater core, which is located under the dashboard. The cold heater hose will be connected to the engine. To identify which heater hose goes to the rear heat, you can look for the hose that is connected to the heater core outlet that is labeled "Rear Heat." The other heater hose will be connected to the heater core outlet that is labeled "Heating Core Inlet." Once you have identified the heater hoses that go to the rear heat, you can reconnect them to the heater core. Be sure to use new clamps when you reconnect the hoses. Here are the steps on how to replace the heater hoses on a 1999 Chevy Venture with rear heat and air: Disconnect the negative battery cable. Drain the coolant from the radiator. Remove the heater hoses from the engine and heater core. Install the new heater hoses. Fill the cooling system with coolant. Reconnect the battery cable. Start the engine and check for leaks.

Hello, You need to open the two breeder valves and make sheer ur getting coolint throw ur hoses. And make sheer you have no air throw your lines.

needs the water system back flushing out, heater being cold is its blocked up some time a few back flushes and forward flushes with a hose pipe should free up the dirt inside, same with the engine and radiator. there are meany videos on you tube to help you understand how to back flush you engie. but do the radiator and engine and heater separate so the muck does not go back into the engine.

Usually a blend door problem, either the control or the blend door itself.

often on the vans with rear air the air dor acuator goed bad and can no longer switch from hot to cold. also the swich itself will often go bad. this can be caused by sticky fingers damaging the inside of the switch. sometimes a good cleaning in warm water will fix a sticky switch

check the vacume / or the vacume regulator for the door exchange from hot to cold there might be a vacume problem.

can you be more descriptive? Doe's it only blow on certain fan speeds? send me a messege and let me know a lil more about it and maybe we can solve this problem.

It is the expansion valve. It is in the rear behind the left rear tire. It is gold in color and in route with the ac lines. Guaranteed fix.
Good luck

you may not have enough refrigerant. a low charge can cause the rear in this dual system to not work for beans. charge with a can of uv and find the leak. fix the leak. evac the system and recharge. i think you take 4 lbs, but check the accumulator sticker. you may want to just change the accum at the same time.

open glove box and open door in the back ,remove air filter and clean,then re install,and make sure to close the door tightly.