Where is the temperature sensor on the ps4 located? (Low Fan Speed)

Hi so my ps4 had same prob fan never changed speeds and it just turned off with no overheat message or beeps meaning the sensors were not working so what i did was add a switch on the fan that boosted the fan speed to 70-80% now its a bit noisy but atleast it never overheats u can check this video on how to add the switch https://youtu.be/wQ-1qsEv6O8

my ps4 is telling me its too hot and turns off but it wasn’t on at all the whole night

I had my Playstation for 2 years now my niece and nephew in law said they knew how to clean my Playstation 4. They cleaned my Playstation 4 with a vacuum hose and cleaned my system with cute tips and and rubbing alcohol and it's been over heating every time I am on it only for minutes and they never took it apart to clean the fans or anything and I called my oldest son and he told me to use a thermometer for my ps4 and when I took it thermometer tempature it literally was reading HI what does that mean it's over heating

yea we just changed and cleaned or PS4 and every time it still says the PS4 is to hot and IDK what to do pls help

I have the issue where the fan would just speed up and make a lot of noise even without being too hot, at all. Just in general, which was annoying, but I figured that if the fan is that active, then it really shouldn't overheat, right. I was testing recently and turned out that I was on for 10 minutes and my PS4 gave me overheat message followed by turning off.

I have opened it and tried to remove all dust, did some work. However, I do really suspect the heat sensor is just really off. So I was also wondering where to look for that part?