1998 chevy tahoe rear a/c blows hot while front a/c blows cold

SOURCE: 2001 tahoe front heater not working, rear heater blows warm air

I have the same problem with my 2001 Tahoe. The front blower is working, its blowing strong, but its cold air even with the temp setting as high as it can get. The rear blows hot air. The engine temp guage is at about 210ish which is close to being normal (220). I just replaced the thermostate a few months ago, I don't know if its bad again, or it I deluted the antifreeze too much and it frooze the heater core, or if the heater core just went bad. Any one know what the cause could be?

SOURCE: ac blowing hot air

the blend door actuator located on the air box (right hand side under dash) is prob. inop. worst case senerio the blend door its self is broken. I have replaced the actuator more than anything.

SOURCE: 2003 chevy tahoe no rear heat

I know the earlier tahoe's have two heater lines running from the engine compartment to the rear under the vechile. Those lines could be clogged or pinched shut. What you do is get two hose locking pliers. Go under your truck, they are two metal lines that turn into rubber and back into metal again farther down the line. First, checked for pinched lines. If none, find where the rubber hoses are, clamp them off, remove from metal lines and drain. Use garden hose to flush fresh water through. When water comes through at high pressure and pretty clear, it should be done. Reconnect hoses, top off radiator fluid and it should be fine.

SOURCE: 2001 tahoe front heater not working, rear heater blows warm air

Notorious for plugged heater cores. Also updated plastic restriction couplers mounted at heater core available from dealer. Try back flushing heater core. Run engine till its at operating temperature then carefully hold the inlet and outlet hose breifly with heater fan on high if hoses are nearly the same temp then flow is good , if not then core is plugged.

SOURCE: Rear a/c not blowing cold, front works fine.

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.