Matt Goda

Ive sorted through Many AC forums and have not found one that helps me solve my problem. So here goes... Got a 2005 f-150 4.6 V8 2WD
A/C quit working 2 yrs ago and at some point the mode door actuator quit too. (Could have been same time but I dont remeber) Blower works fine which seems to be the culprit in most forum answers and the recirculator actuator works too. I finally had the pizazz to tear off the entire dash and replace that door actuator. (Of course it couldnt have been the one accessible behind the radio.) I figured by now the ac compressor would be bad as well. So I replaced everything the condensor, receiver/dry, and compressor, but the compressor clutch will not engage and the ac will not come on.

1. Lights for AC are on.
2. Blower is working
3. 40psi of freon
4. I can manually turn clutch.
5. I believe the temperature actuator (one behind the radio) is working bcuz the car will get hot air.

Just no A/C. I read about hot-wireing the low pressure ac port on receiver/dryer but dont understand how to.. I'm not keen on hot-wireing but I just want to make sure the clutch will engage and the AC works. I understand fuses and resistors but dont know what check. Ive read there are a series of things that must be right for the resistor to engage for the AC but i just dont know what to do.
Any help would be greatly appreciated. Its florida and its now 90 everyday.
Oh and the check engine light is not on.
Thanks from Tallahassee!!

nrivera04

Paperclip to jump the wires.

Check the ray in the drivers side fenderwell. It’s kind of hiding in a small box. Common culprit for failure.

Eric Kleven

the AC relay is on the driver's side fender next to the ABS module and air snorkel. get a test light in there and make sure you're getting signal/voltage to the relay to even turn on the clutch.

redfishtd

Any parts house has a relay that will work .

Of course the relay will not pu until pcm supplies ground signal. Pressure switches report to pcm . So does ac control system . Get a new relay see if that works take it to parts house for match . If that doesn't work break plastic case on old one and push relay mech by hand-- clutch should engage . That will tell you which direction to look at . Plus you can easily see how to jury rig it for awhile for emerg cooling
If you are wondering ,that diode is there to suppress the heavy kick back of the clutch coil when released . When the field collases it kicks back an opposite polarity of the one that was applied .

redfishtd

If you are going to jumper its best to use a heavy fused jumper . Less smoke/damage that way if you screw up . To jump in a ground to coil you can use a good size 12ydc bulb as the coil draws very little. But the clutch draws a lot . Only use jumpers if you are very very electrical minded .Remember once you let the smoke out of an electrical device its bad --LOL .

Matt Goda

I appreiate your response.. I did find that small box. And jumped the ac clutch relay. I was expecting the clutch to engage but the clicking i heard sounding like it was coming from the engine top end. I used the fuse locations provided by the manual too.
Im at the point where i need to either find and check all the relays for the ac or take it to a professional.
I did hook pos/neg directly to my ac compressor and the clutch engaged so i know ot works its just getting the pcm to turn it on!

Thanks for you help I really did need it, used it, and appreciate it.
Keep on keepin' on. Matt