See if the Compressor is running (clutch) at the problem point:lewisbryant wrote: ↑Thu Jun 03, 2021 8:15 pm Does the air restriction only happen when the AC is on? Does it happen after 30 minutes with AC off? Only reason is that I've seen a car before not nissan where the evaporator has frozen up solid with ice and blocks the air flow
This is usually caused by a faulty evaporator temp sensor as this sensor when it gets to 3 degrees it shuts the AC pump off and as it warns up to about 7 or 8 degrees it turn the AC back on
If the Auto amp is reading say ambient temp then it will keep the ac pumping and it will cause the evaporatof to freeze and block up with ice causing low airflow
You can check this temp sensors reading with a scantool communicating with the hvac module
CONTROL BY A/C AUTO AMP. (from diagnostics)
Low Temperature Protection Control
When intake sensor detects that evaporator fin temperature is [−5.0°C (23.0°F)] or less.
A/C auto amp. requests ECM to turn the compressor OFF, and stops the compressor.
When the air temperature returns to [1.0°C (33.8°F)] or more, the compressor is activated.
The intake/Evap temperature sensor measurement range is from -20C thru +40C in 10C steps (degrees).
I'd of thought if the Evap was freezing up at some point a puddle would appear under the car?