What is this thingamagig ?

[NorCal Hal]

Does anyone know the purpose of the electrical micro switch or relay on the end of a white wire in a bundle of 4-5 wires behind the front passenger side instrument panel, fire wall... It was not connected to anything other than the white wire. The marking on it are "low", "world magnetics","PSF109""20883", "C17D8" and more.



Harold

[NorCal Hal]

Does anyone know the purpose of the electrical micro switch or relay on the end of a white wire in a bundle of 4-5 wires behind the front passenger side instrument panel, fire wall... It was not connected to anything other than the white wire. The marking on it are "low", "world magnetics","PSF109""20883", "C17D8" and more.



Harold

[Mutha]

Harold,
The Switch you have found is a vacuum/pressure switch, manufactured by WORLD MAGNETICS CORP. The part Number is PSF109.
This is a very common pressure switch and can be used in hundreds of pressure monitoring applications that require a "OFF-ON" set point triggered by pressure via an electric input.

I do not know what it does in your specific RIG, but maybe one of the Alpine owners is familiar with what it controls and will chime in here. My guess is it has to be a part of your Air Conditioning-Heater system.

Here is a Spec Sheet on the switch:
Switch Specs

Good luck - Glenn

[takepride]

Sounds like the switch that powers up the braking system when the ignition is off or gets cut, allowing the driver to stop.

Secondly it may be the switch that controls a vent for the dash AC, opening and closing it for circulating or re-circulating the air.