Why is it that my climate control unit sucks?

I feel like it doesn't really work that well. Fan speed used to increase only marginally from low to high, but the fan was always spinning. Recently it stopped working completely.

And it only blows luke warm air on cool, but it does blow hot air on hot. Also, the air blows mostly at my feet. Air through the upper vents is almost nothing.

So why does the climate control in my car suck so bad? What's broken? Can I upgrade to a C4/ C5 unit and appreciate a difference?

I forget the year of your vette, as I recall, i'ts a later one...77+ and therefore has that plastic controller assy, here in Florida I have seen 3-4 of them all falling apart from just plain age and dried out plastic, the unit itself fails not only the mounts to the dash, but where the cables join in and where the vacuum lines plug in the back section,...you will probably find some broken off ports/pins

on my '72, I made my own console/control panel long time ago...gave up on the thumbwheels contraption even though it worked fine....

:beer:

Well....The climate control in your car sucks so bad because it sounds like it isn't working correctly. Upgrading would be nice, but I think it's going to be much easier, and cost effective to get the system that's in the car working properly. The C3 systems can work well, I'm in Florida and in the summer, my A/C gets cold enough on lower settings that the wife asks to turn it down cause her toes are cold! If they aren't working right it doesn't matter what system you have. I have an 04 Tahoe and that HVAC system has cost me $800 over the last year for blend doors, control panels and other BS and last night the heat only works when you're leaving a light!!! :bomb:

It sounds like you've got a few issues going. First, the fan. Could be several things, but I suspect the high speed resistor could be bad. You should have a noticeable difference from low to high. A bad high speed resistor (located in the top of the A/C box) can cause the fan not to go into high speed. There's also a fan relay on the fire wall above the A/C air box that can cause issues, but I think that usually ends up with the fan not working at all.

Next, luke warm on cool. Likely the hot water shut off, on the passenger side inner wheel well. Follow the heater hose to the vacuum actuated water valve. That's the usual suspect. Check to make sure your getting vacuum on the valve when your temp selector is in the cool position. If you are, make sure the valve is working. It should be closed when cool is selected. That works by a vacuum switch that is actuated by the temp selection cable and is usually located on the top of the air box inside the car. Pull the glove box to see it. Another culprit is the fresh air valve (another vacuum actuator) that's out side on the fire wall. It's the vent that lets fresh air in. Check the vacuum there too.

Only getting air blowing on your feet is because one of the vacuum actuators (for the blend door) isn't working correctly. Because the actuator is bad or it's not getting the proper vacuum signal. These are just a few places to look, and what I've found to be pretty common problems. The service manual has the vacuum diagram in it and it's a great help in trouble shooting these problems.

Awesome, thank you very much. I'll report back in a few days.