jessejames

Hello my brother in law has a 1996 Silverado that the A/C is not working on. It blows air but no cold. He recgarged it but that didn't work. The truck was in an accident and the dash popped out, had to be re-connected. Not sure if that was the prob, but does anyone have any idea where I could start looking to help him out???

Thanks in advance!

48fan

Sometimes people put the freon in but forget to put the oil in as well. When you loose freon you loose oil so you can try that (the oil lubes the compressor). This is most likely not your problem but it would not hurt to do it; you'll get more life from your compressor if you do so.

Anyway, start the vehicle without the A/C on. Then turn the A/C on full blast and check to see if the Compressor actuates (you should hear a click) and the RPM's should drop for a second. If the compressor actuates and the RPM's drop then your compresor may not be the problem. If you do not hear a click and the RPMs do not drop then you have a compressor problem. The Air gap in the compressor clutch may need to be adjusted or you may have some bad connections. If the air gap is fine and the conections are fine it could be internal.

Another possibility is you may not be getting a heat transfer in either the Condenser or the Evaporator. The condensor is an easy check, your condensor is located in front of the radiator (it looks like another radiator), check to make sure nothing is in front of it (like a plastic bag)and make sure the fins aren't bent. If you noticed the vehicle running hot this may be why because it blocks the air flow to the radiator. If thats fine then you need to start checking pressures. If you have a manifold guage set you can do this otherwise you can use the "hands feel test". To do this you need to know where all of the components are located.Feel the lines on both sides of the condensor, the Compressor side of the Condensor sould be hot and the outlet side of the Condensor should be warm. Next in line is your orfice tube or expansion valve.

Another problem could be that the orfice tube or expansion valve may be bad. Your vehicle has one or the other, not both; if you can locate this part and feel the lines on both sides of it then you should feel warm on one side (condensor side)and cold on the other. If you do not feel this then you may need to replace this part.

Really the best way to trouble shoot this is with a manifold guage set but the "hands feel test" works just as good if you know the location of the parts.

This is a start.