Another AC question

[stl87]

Just updated my ac with a duel keull system from Griffiths ( 2 new wheel well condensers)
Already had the barrier lines, comp, evap, press switch done by previous owner

On start up I get 40 Degrees in about 5 minutes.
After driving 20 minutes vent temp climbs to 60 and stays there

After parking overnight same thing over again 40 on start up then up to 60 on driving.

Any ideas?

Thanks

[walt]

Pressure readings might tell you something.

[brianlay]

Either the thermostat is faulty or the probe is not positioned correctly.
I suggest you contact Griffiths.

[GH85Carrera]

I bet the evaporator is freezing up. Do you notice a slow down of the air blowing out? If it is not 95 degrees or hotter, and the fan turned to max, the evaporator will freeze if your temp sensor in the evaporator is likely not placed right.

I have Griffith’s temp sensor and it has an LED that lets me know if the compressor is compressing or just free wheeling. If it does not freewheel occasionally it is likely to freeze up, unless it is very hot outside and the fan speed is max.

And pressure reading for low and high would help.

[wazzz]

When vent temp is climbing to 60, stop the car, let engine and AC on and go check in the engine compartment if the compressor clutch is engaged or not. It is easy to see if the pulley is free wheeling or if the part facing you is also turning with it. If this part is not turning (free wheeling pulley), chances are the Hi-side pressure is too high and the Hi-Lo pressure switch has cut power to compressor clutch in order to safeguard it.
Or, as Glen suggested it, evaporator is freezing up.

[mziggy16]

If the evap is freezing you might try turning the temp control up one, maybe two clicks when the temp begins to climb.

[kuehl]

All of the above