Thread: SLS COmpressor- strange noise?

While fitting the SLS By Pass Kit from Hard range with my head next to the sls compressor, system deflated, compressor not "pumping" but from the compressor box comes a strange soft noise like a high speed clockwork timer.

When my hand was placed flat against the bottom of the compressor box the volume of the noise reduced.

Any guru's out there know what that noise is? is it a normal?

(yep did a search nothing relevant popped up hence the question).

Thanks in advance.

Not sure if that's normal, I'll have to listen to mine although I've never noticed it when under the car. I do know it seems to monitor the pressures or levels of the airbags when switched off, but won't pump them up when the car is not running as I think it checks for battery voltage, which I discovered when putting the battery charger on or connecting the dual battery I forget which. I think it will bleed them level when turned off though, might be what you heard?