I've got a 1990 f150 here. AC hasn't blown cold since I've owned it. I'm working through diagnosing what is broken but I have absolutely zero clue what I'm doing when it comes to AC components and the system as a whole. What is this housing, is it okay if it is cracked, or is it the reason my AC isn't blowing cold. Help would be appreciated, its pretty hot without it lol.

 

That is the evaporator core housing, And that part hanging off is actually a vacuum reservoir that is supposed to be glued on. If you look inside that crack, can you see the evaporator core? Or is it still covered.

 

I believe so. Is this it?

 

Yep, that would cause a lack of cold air. You can try gluing or plastic welding it back on, but if that doesn't work, you'll just need to replace it.

 

Got it. Ill try to glue that back up. Should I recharge refrigerant after I do that?

 

It can't hurt to hook up some gauges and check if its low, but that cracked evap core housing wouldn't cause any loss of refrigerant.

 

Try watching a bunch of A/C service videos regardless of vehicle make/model. High side/ low side numbers and behavior will be the same. Compressor activation and temp at the dash are all similar across most vehicles. Just adding refrigerant may not result in the best performance. If the system was just recently working and is a little low, you might get away with a simple top off.

If not, it's best to vacuum down the system and make sure it holds vac. Next you add the exact weight of refrigerant required. Is yours R12 or R134a? You have a digital scale?

Its possible to cut corners and make it work. Your mileage may vary.

Good luck.