Aux. Vac Booster Pump Troubleshooting

[betterair]

I have a booster vac pump I am trying to Diagnose, as it no longer cycles (powers up when the ignition is turned on)

The pump works when I pull the relay out of the circuit and apply 12 v .
a replacement relay did not provide any goodness, so I need to trouble shoot the pressure sensor or replace it IF i can Identify it.
Heres what I have
Vac pump (and disassembled relay):


and pressure/vac sensor/wiring connector that threads into the main vac line and connects into the relay.:




I Appreciate any help in identifying the pressure sensor p/n ,and where to source one and any troubleshooting suggestions.
The vac booster was installed on the car to supplement the brake system vacuum due to the 993SS cam on lift.
Thanks

[betterair]

tested the relay again......problem solved .Vac booster pump back in action.
Still need a source for the sensor if anyone has a suggestion.
Thanks