Background
The pressure switch is a normally closed (low air pressure) switch that connects via a 3.5 mm jack into the back of the mounting plate. When the switch has above 90 PSI it opens. The ATC control board looks for this open signal to indicate there is adequate air pressure.
Air Pressure | Switch State | Error |
|---|---|---|
<90 PSI | Closed | Low Air Warning |
>90 PSI | Open | Nothing |
Table of Contents
Disconnect and/or replace the sensor
Reason: The air pressure sensor is faulty.
Disconnect the 3.5 mm jack, which opens the circuit and allows the machine to run.
Recalibrate the sensor
Reason: The air pressure sensor needs to be calibrated.
Remove the boot and adjust the switches threshold through an adjustment screw.
Replace the sensor
Reason: There is a short in the circuit.
Find and repair the short.
An extreme solution that my be irreversible would be to cut the wires connecting the female 3.5 mm jack to the ATC control board and use wire nuts or electrical tape to cap them off. As long as the short was past where you cut, you will break the circuit and the ATC control board will see the “open” it needs to operate.