Last few days i had to work in Phoenix on a project . My A/C had been acting strange last few weeks in AZ heat some days 42 deg coming out of vents other days 50 - 52 . No highway driving just high ambient temps. Taking trip to phoenix didn't run A/c in morning . In the blazing afternoon heat best coming out of vents was 55deg , driving at highway speeds. Plus when RPMs got up i heard a whirring noise . Got home and it was putting 51 deg out sitting in driveway . I was about to text my service guy at my local dealership to take it in . I thought i better check the cabin filter before i do. Sure enough it was very dirty . This is the original filter 3 years old. I have only driven on dirt roads with this truck a few times . Installed new one i had bought a year ago and had stashed away . Put it all back together start truck let idle a few min 43 deg . Next day way home from phoenix 42 deg the entire way. It was 110 ambient and high dewpoint . Plus the whirrring noise is now gone, can only speculate the dirty filter was increase the refrigerant pressures taxing the CCRRAAPP out of my compressor. I will be changing filter every spring from now on . I told my buddy and neighbor about it . He a 2019 f150 as well . i will be changing his on Sunday morning .
Excellent advice. I can see that I have to start doing more maintenance myself. Last truck (2006 Tacoma) there was prescribed maintenance at 5K miles, 10K miles, then a more complete maintenance at 15K miles right in the owners manual, to be stamped by the dealer upon completion of services for records. Done by dealer. Repeat, repeat, repeat, with more involved maintenance at certain higher mileage intervals (like 60K, 90K, etc.). I paid for each of those services. So when I bought the '18 Raptor new I signed up for a maintenance contract, figuring it would involve similar services and save money by paying up front. BIG BIG BIG mistake. They only do oil change and tire rotation. Not even engine or cabin air filter changes. At perhaps 38-40K miles I had a transmission shifting problem that suddenly made the truck undriveable, threw the wrench icon up on the screen. Took it to the dealer, they could find no problem and it has not recurred. But they recommended a "transmission flush and refill". So I inquired as to when that is normally recommended to be done, and they said "70K miles". How convenient. It seems that ALL services (plugs, air filters, gearbox flushes, etc.) aren't recommended until 70K miles, right when my pre-paid service contract expires. Guess I'm a sucker, and in my attempt to cover myself I got sucked in.