No heater?

Checked fuses all of them are good I disconnected the fans and gave them direct voltage and the fans did nothing but the motor in the fan just made a humming noise so I know the fans are bad but that only fixes 1 problem I still don't know why I'm not getting any heat or ac/ no blowing at all

1998 Buick Park Avenue 6 cyl Two Wheel Drive 310000 miles

After a mechanic tried charging me a ridiculous price for NOT fixing my car, I found that my heater no longer works.

The climate controls work and the fuses are good. The thermostat is working. I see no heater hose problems but no hot water seems to be flowing thru my heater coil.

What do I look for?

Yes and Yes

I CANNOT TURN THE HEATER/AIRFLOW/FAN OFF
INSIDE THE CAR THE OFF BUTTON INCLUDING THE INSTRU. PANEL IS NOT WORKING, MAYBE A FUSE? OR NOT?

When I turn on the automatic control, the heater or ac, the cold air or heat comes out the defroster an heater slots, not out the slots in the dash.

There is a vacuum hose (90 degree, molded) under the hood (near the master cylinder) that easily gets knocked off. Look closely it's small and easy to miss.

Since replacing the small bypass hose and fitting into the intake manifold, the heater won't blow warm air regardless of the temperature setting. Also, the temperature display on the dash blinks for a short time after start up. Is there any way to reset the temp control module, or should I assume it is fried?

Last week two problems happened. One was a battery, that didn't like the -14 F overnight. The other one is barely any heat coming from any outlet, floor, dash, defrost. It does have dual zone HVAC for DR/PASS sides. The night when it got so cold, my antifreeze was only good for about -10 to-12 F. All freeze plugs and hoses survived the chilly engine.

After installing another battery for my 60 mile drive in below zero temperatures, I almost froze! I have replaced the thermostat with a 195 F. Added antifreeze to better protect the engine. I still have the same problem of minimal heat and cold air on Pass side whether Dual zone is off or on. Vacuum controls seem to work to direct air to all the right places. Luke warm on DR side and ambient/cold on PASS side in all positions.

I have tried to access the error codes y trying "OFF" and "High temp" at the same time. No change in display, so this does not work for this car.

I believe the problem is with a blend door or electrical actuated solenoid.

If so, where does a person start?

Coolant flow does not appear to be my problem. Both hoses appear to heat up. Below 20 F the PASS side is cold, DR side is warm, not hot. Around 50 F both sides are warm on low fan. High fan the PASS gets cold and DR side is warm, not hot.

Sounds like "open dash" surgery! That is what I was afraid of. Luckily the PASS side seat only has a couple of wires and four bolts to remove.

Thank you, jacobandnicholas!

Hello, I have a question. I recently purchased my used vehicle and when I did, the heat worked great. Now for whatever reason, the heat will only blow out when the car has been turned of for a significant amount of time. For example, in the morning when I start the car the heat comes on. When I leave for work after an 8 hour day, the heat comes on. But if I turn the car off and say turn the car back on a few minutes later, the heat will not come on. All my lights are lighting up and I occasionally here a click like it wants to come on, but it does not so I did not think it would be a fuse but I am really not sure what it could be. Your help is greatly appreciated.