AC was cold then not. Troubleshooting help needed
#11
05-31-2019, 12:52 AM
Pressure switches can fail either open or closed. They can also open or close at pressures outside the range they abre rated for. They usually come with c.o and c.i. ratings listed on their info tag. You have to gauge up the system to determine whether they're operating within their respective ranges. Bypassing switches doesn't always tell you everything. Don't get me wrong; I sometimes bypass switches and overloads in my line of work. (I've been an HVAC service tech for 40 years now). A pressure switch can be replaced only to find out that it was a faulty schrader core under the switch. Just be aware that knowing what the pressures are definitely helps in troubleshooting.
One of the reasons I shorted the leads was to confirm if the rest of the clutch control circuit was working, which it did.
Last week I was able to confirm (I think) that there was enough refrigerant in the system with a gauge set so that is how I felt, in combination with the shorting of the leads, that the switch was bad.
Still learning!
But you mentioned the possibility of a bad schrader valve. I did notice that there was some oil covering the original switch and around the schrader valve. I'll have to make a note of it possibly being bad. If/when i have to get the AC system evacuated, I'll look at replacing it.
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