So I’m working on a 2017 ford f-150 xlt and the truck came in because the high side fan was coming on and being really loud I hooked up the ac machine and saw that the high side pressure was starting at around 250 psi then would jump up close to 400 then the fan would turn on and the pressure would come down back to around 230 and then turn off then the pressure would climb again to around 400 and the fan would turn on again so we replaced the expansion valve and condenser and it was still doing it so after some more looking around found that the low side fan was not turning on at all and started smoking when commanding it with the diagnostic tool so we replaced the fan and radiator aswell because it broke when taking the fan out so after putting it all back together and burping the cooling system out everything was working normally the fans were fine and the compressor was on and blowing cold after turning it off to put the cap on and closing the hood to go on a test drive while driving I seen that the compressor was not turning on at all so I bring it back into the shop and commanded the compressor to come on and it did but it was doing the same thing as before with the fan and pressure going super high then coming back down but when I stopped commanding the compressor to turn on it would not turn on by itself so I check the fuses and relays and there were all fine changed the high pressure switch and it still did not turn on check the ambient temp sensor and it was fine aswell but I did notice with the compressor of the high side was sitting stagnant at 165 psi and low side around 90

vehicle dos have correct freon and correct amount aswell.

 

Welcome to the forum.

 

I'd start by checking the low fan connector for signs of overheating. If that fan developed restance in the bearings, or had something stuck in it that prevented spinning for a while, it would have been pulling extra current.