Strange high side pressure reading

[canadmin]

1999 GMC Sonoma 4.3. AC is now working great and the low side reading is good but I'm getting 0 psi on the high side. Its not the gauges or the lines cause I was using them yesterday and they were fine. Everything else is good. ??? Can anyone explain this?

[Cusser]

I say your connector is not pressing/opening the high side service valve.

Is there a shut off valve on your high side connector? If so, is that shut?

[tbirdtbird]

What he said

[canadmin]

Thanks for the replies. I will check that out.