1998 Y33 AC switches to heat randomly

[Sannamii]

Y33 Automatic AC runs super cold, but then switches to heat/hot air mid drive, after messing with the controls it will go back to being cold. Sometimes will once again switch to heat, sometimes will stay cold. Any suggestions? Or ideas? Anybody ever had the same issue?

[VStar650CL]

Is it actual heat, or just outside ambient? I don't have any Gloria documentation, but most Nissan A/C's have a TXV Valve. If you're losing airflow along with it going warm, there's a good chance the TXV is stuck open and causing your evap to freeze. If it's actually switching to heat, chances are you have either a mix actuator with a worn out position pot or a bad control head.

[98_Q45]

I’d agree with the above. I don’t think an air mix motor would do that though. Probably moreso the evap freezing up. It could be covered with dust. I know with home a/c if it does that, try rubbing it at 70-75 versus lowest it’ll go.

People often turn their car a/c lowest it can go in summer, but it’s better to run it not at the coldest temperature. Coldest temperature is moreso when you want a/c cold and it’s only 70 degrees out. If it’s 90-100 degrees, it’s going to overwork itself trying to get to 65 degrees. I have GM vehicle, and it will get a little warm every so often. Sometimes a dirty interior temperature sensor will feel it’s too cold, and then try to warm it up to get to temperature.

I’d try air dusting that first, as a/c diagnostic isn’t cheap or easy