I have a 95 SC. My heater blows cold air, even when thrmostatt is maxed at 90 degrees. Radiator is full of coolant/water mix. A/C works fine blows ice cold. What could be the situation on the heater?

blocked heater core, malfunctioning heater blower doors or HW valves - but you probably already know this. There's no chronic problem with a magic solution here.

Your car been sitting a while?

Albertj

could be any of the following-
heater core hose has a clog or is collapsed.
actuators are not turning to allow hot air to flow into the cabin. (most likely IMO)
your WP is broken. (car would overheat)
temp control is broken.

if the air ice cold, or just not hot?
what is the ambient temp and car temp when you are running the heat?
do all the vents blow the same temp, or does the dash/floor feel different?

damn albert, you beat me to it by mere seconds!

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Albertj

Car has not been sitting. It's daily driver. Ambient temp is 50-60 when I attempt to use heater (Hey, I'm a weenie this is Southern California), but air is ice cold with compressor on, very cool with just the blower. All vents blow about the same temp. It has to be the actuators or the core. Probably the core, since the directional controls (bi-level, upper, lower etc) seem to work fine. How hard is the core to remove?

Just curious, if you're in So-Cal then why do you even need the heater? Here in OH I still have the windows down until it gets to be like 40*F.

Is the heat still off if you turn the temp all the way up?

Maybe the cabin air temp sensor quit? and is telling the car that the cabin is warm, so it runs the AC full tilt and won't turn on the heater.

Albert

If the cabin sensor failed, wouldn't that just cause a problem in auto mode? If you manually increased the heat, shouldn't matter what the sensor sees, imo.

I'm betting it's something to do with mechanical directing of hot air (flap/door, or actuator stuck or failed. Maybe remove some of the plastic under the dash and see if any heat comes out.

I'm saying actuator , i have to turn mine by hand during the season change(Summer to winter)

OK, guys here's an update. Outside temp 49 degrees. Thermostat on 90. Climate control on "Bi-Level". On bi-level the two middle air outlets on the dash blow hot. The outside dash outlets, floor, door and rear passenger outlets blow ice cold.. Does this narrow the problem down?

You have an actuator not working. The problem is I can't tell you right now which one, there are 5 total. Their not to hard to access.
Let me look in the book for a while and I'll get back to on which one is the problem child.
There are some excellent pictures of these actuator motors in a thread on this board somewhere. Will have to search or whoever posted them might be able to help also.

Does everything work normal in the Defrost Mode. ?
Air to windshield and some to floor only ? Air shouldn't come out of any of the front vents in defrost mode.
Need to know for troubleshooting.
With Controller in Auto position and outside temp lower than cabin temp, where if anywhere are you getting heated air ?
I know you said if you manually command full hot (90*) your getting the mixture you describe, but what happens in AUTO ?

The 95 must be different than mine (98) because I don't have a "Bi-Level" setting and there's nothing in the factory manual discussing bi-level.

FYI, The HVAC programmer energizes the air mix actuators to perform certain functions. (open, close, mix, etc.) Need to determine what's not doing it's job.

Look at this link, I know it won't solve your problem but it gives you a view of the actuators,
http://rivperformance.editboard.com/interior-f20/write-up-hvac-assembly-t2500.htm