Low Side Quick Connector - Do They Clog or Break?

[cloves]

Hi everyone,

I was working on my car today. I vacuumed out the system and left the vac on for 30 minutes to make sure I had no leaks. I then connected my can of freon to the yellow hose, also put some UV dye in the hose, and bled the line at the top of my manifold. Then started the car and slowly opened up the freon can. My low side gauge started to show a rise in freon. But my compressor never kicked out and no freon made it over to the high side.

So then after trying to figure out what was going on, I took my hoses off and looked at my low side quick connector. Both (low and high) have the pins and a small hole. So I took compressed air line and blew air through the high hose and quick coupler, air went in and out. I assume the hole is slightly larger since that side can take liquid but who knows.

Anyways I then took air and blew it the low side quick coupler. No air was going past. Also did it with my mouth and again no air. Took the hose off and just blew air into the coupler and no flow. Is this normal or could my quick coupler be clogged? Or shot? Its a harbor freight set.