AC and Recirculation Light Doesn't light up?
 

New to the forum and need some help. I purchased my 2004 F150 about a year ago, I put a new head unit and speakers in and a small little sub about 2 months after getting it. Shorty after that the AC would not work anymore but did before. Now if you press the AC button it doesn't light up or come on, but when you press the recirculation button the truck will recirculate the air but the light will not come on. I'm kind of stumped on what could be the problem. I checked all of the fuses and none of them are blown. The truck isn't a daily driver or anything so I've been putting it on the back burner for a while and finally am getting around to it and i'm pretty lost.

Any information or help would be VERY appreciated.

Any thoughts from anyone? Does anyone know if the ac dash control units ever go bad or anything? or could it be some type of issue with the compressor or refrigerant level being low? it cool really well when i first got it and for a month or two afterwards. but Since i put the cd player and stuff in it hasn't seemed to work. There wasn't any issues when I put the cd player and stuff in so i figured it isn't that.

Any help? i'd like to at least tackle any issues i can before i'd have to bring it to a shop.

So during my lunch break i went home and made a video sort of outlining the problem.

The fan will blow, but when you press the AC button nothing happens and the light doesn't come on. I also show that when i put it on max ac, the recirculation part will work and blow more air, but neither light for the ac or the recirculation comes on. I also press the recirculation button and you can hear it blowing more. so neither light for the buttons works, but the recirculation apparently seems to be working.

After the last video, i also turned the fan down to one so i could hear a little better and pressed on the AC button and held it down for a few seconds. I could hear something sound like it was cycling on and off (compressor?) and also made a video, you can hear a 'clicking' sound around 3 or 4 seconds.



So a question, if the freon is low, could it be causing this clicking sound by trying to start but stopping because of a low level and repeating?
If thats the case would that be a reasoning for the lights not displaying on the dash control unit.

or could the control unit itself be the problem of not sending a constant signal to the compressor? i'm just trying to brainstorm and think of potential causes.


any help or advice?

That sounded (thre clicking sound) like your compressor clutch kick in and then right back out. 1st thing you need to do is check the pressure on the system. You should be able to check it static (without the engine running). The system should be (my experience, as a somewhat general rule) approximately what outside temperature is. Meaning if outside temp. is 90 degrees, system should be about 90 lbs. pressure on both high and low side if it is full (not under or over charged). If is quite a lot under that, it's very possibly just low, but if it follows that rule, don't go adding, thinking "more must be better". It won't follow it exactly but is a good general rule for checking pressure when the system won't fire up.

IF that is not the problem, come back and I'll give you instructions for disassembling the button and cleaning the contacts. I've done it on mine and have done it quite a few trimes on the remote controls for the ceiling fans when they get a little sluggish. They're the same type of soft touch control. But don't do that until you know the system is fully charged.

And just a thought, when you put that head unit in you removed the center dash and possibly unplugged the leads to those switches and maybe didn't get the pigtail locked back into position and maybe it's loosened up some?

Sorry i haven't gotten back to this, i've been traveling for business a lot lately. I finally found a co worker with one of the gauges i can use to check the pressure. I will post them as soon as I get the time to take the measurements.

Thanks for the information and advice, i at least have a direction to go with it.