The A/C in my truck has quit working over the winter. It just blows vent temperature air no matter how cold you set it. The heater works excellent even when the truck is cold though.
So I took the glove box off and took the plastic cover off of the core and it has green in between the fins. Possible coolant leak? The radiator fluid doesn't seem to be low.
I'm gussing that the core needs to be replace, it costs around $100 dollars though so I want to be sure. Will my A/C system need to be charged again?
Thanks for any help!

 

AC has nothing to do with the heater core. The green is probably corrosion on the fins. The AC system has an evaporator under the dash which provides the cold air source, it does look a lot like a heater core.

 

Oh OK. I don't claim to know much about HVAC. This must be the evaporator core then. Is this something I can fix myself?

 

I took some pictures of what I'm thinking about and put them in my gallery.

 

That looks like your heater core to me. Located behind the glove box. I would have the A/C checked but then again i am an idiot when it comes to a/c, but I have changed two or three heater cores and they are a piece of cake. Bu that is not your problem.

Chris

 

I would try to see if the magnetic clutch on the AC compressor functions. Have someone cycle the AC on and listen for a clicking sound coming from the compressor. If there is no click you may be looking at a problem in the AC compressor clutch circuit.
If it does click and run, you may have an issue with low refrigerant. You need a license to deal with refrigerant, so a service shop would need to work on it. Whatever you do, don't let anyone tell you you can top it off with propane. It'll work, but you'll have a bomb waiting to go off! Unfortunately since the manufacture of R-12 was banned internationally back in the early '90's, a fill up on R-12 will cost you an arm and a leg. The other option if you are low on refrigerant is an R-134a conversion, but that would be extremely expensive. I'm no HVAC tech, but I do know the basic theory and operation of the systems.

 

I'll check tomorrow and see if I can hear the AC click on/off.
It was converted to R-134a a few years ago so it shouldn't cost a whole lot to get it topped off.
The AC compressor is inside the black round canister that is under the hood on passenger's side, right?

 

Just to clear a few things up for you... your heater core behind the glove box has absolutely nothing to do with the A/C, if your heater is working to your satisfaction, you should probably just leave it alone. If your A/C has been converted to R-134a, you are correct, it is relatively inexpensive to add coolant. However.... you should address the problem, not the symptom. If your A/C was working fine before, and doesn't now, their are a number of possible reasons why, so start with the easy ones and go from there. If your A/C compressor (that's the thing above your power steering pump that looks like a motor and has two hoses coming off of it) appears to be cycling fine (should not jerk or clunk when engaged) and doesn't whine or sound like it's grinding, then maybe it's just your obvious coolant leak. If it is a bad compressor, you will have to replace it and all inline filters as well as the condensor and FLUSH THE SYSTEM to get rid of those fine metal grindings in the system that will just tear up another compressor if you don't. Of course, now you will have to completely recharge the system since you had to purge it to remove the compressor. Contrary to popular belief, once you charge your system, it should STAY charged. It is not normal to lose R-134a coolant over the winter months. If it doesn't, you have a leak and a technician with a "sniffer tool" needs to find it. Do yourself a favor, before you attempt ANY repair operation on the A/C, educate yourself about the parts you are messing with, do not guess at it unless you have a bottomless bank account.

 

OK. Finally started checking some stuff with the AC. First thing I noticed is that the Compressor clutch is not engaging when you turn the AC on. There are two wires running to the top of the compressor. I guess this is what engages the clutch? Do I just check for voltage on these wires to determine if it's the wiring or the clutch? Thanks for your help.