Aveboi173

When I leave my AC on too long the car temp slowly goes up what can it be? Someone told me thermostat I have a 2003 CL type s

Thefireball

Is the fan(s) behind the radiator turning on at all? Run the car for a minute, and verify that they are.
Have you checked to see if your coolant level in your radiator is low? There's not really a stick like there is for oil or transmission, but when you pull that cap off (don't open it while it's hot), you should see some liquid floating at the top. If you can, try pouring some coolant into it and see if it over flows, or if it chugs it down. If you're low, you have a leak some where.
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Aveboi173

Everything working fine I’ll check the coolant in radiator but coolant in reservoir good

Thefireball

I'm probably wrong, but I think the reservoir is just to catch overflow. Top off the coolant, check for leaks. Then run the car, check for leaks underneath, then continue filling it up while it's running until it starts to overflow. Wait for all of the bubbles to stop appearing, and top it off until it's full.
However, as soon as you see a leak, stop, and figure out where it's coming from, if it even is a leak.

619rcr

restricted airflow would be my first guess after fan. is this just sitting that it happens or all the time? is this an automatic by chance?