Need Advice For Fan Switch Control Ac Heater

[Erin664]

I have a 2007 Nissan Altima 2.5
The fan switch control for the AC/Heater comes on like clockwork but only about 20 - 30 minutes after driving the car. I have manual temperature controls and replaced the fan switch control assembly with no luck. I have had better success when I place a space heater in the car on the passengers side pointed towards the console for 30 minutes then remove it and start driving, the heater fan motor will start after only 5 minutes of driving, sometimes right away. It will run for hours once started and sounds perfect, but if I stop the car for an errand leaving it off for 15 - 20 minutes, it will take 15 - 20 minutes for it to come back on. During the summertime, it is the same pattern with the AC - it will take 5 - 10 minutes for the AC to come on, but winter time seems to take much longer. Please advise. Thanks!