i know very little about the AC system.

on our last road trip the AC in one of our '04's starting blowing a little warm. so, we stopped and i picked up one of the $50.00 AC refill bottles with a gauge on it and checked the system. gauge read low so, i recharged until the bottle gauge gave me a good reading. after doing this the AC blew colder air and off we went. this lasted us a week and then i needed to do the whole process again using most of the rest of the first bottle of refrigerant that i had bought.

now the AC is still blowing cold air but there is clicking/buzzing sound coming from the engine bay. when this happens the AC pressure gauge that i have hooked up will shoot up to the over pressure range and then drop back down to normal pressure after the clicking/buzzing stops.

anyone have any experience with this?

 

Can you tell what is causing the clicking? Is the center of the compressor clutch spinning when you hear this noise?

 

Pressure drops when the AC clutch is engaged & rises when the AC clutch is disengaged.

 

the AC is on and blowing cold air. my daughter is out with the truck right now so, that's the best i can do.

 

so, that would seem to indicate the clutch is momentarily disengaging. why would it do that?

 

There is a low pressure switch that will cycle the compressor if your freon is too low. Also a high pressure switch if your pressure is too high. Also possible you have air in your system.

 

I can easily see this happening when people use the DYI refrigerant-in-a-can wrong.

 

thanks for the suggestions.

i'll check out what i can and check back in.