Yet again I accidentally left my supercharger on and drained the battery flat.
 
It has an aftermarket switch wired directly from the magnetic clutch to the battery. I was wondering if the factory setup ran via a relay triggered by the ignition?
 
I am considering using a generic relay, so the charger will turn off with the car, my only concern is reliability, if the relay were to fail while cornering it could be fatal... has anyone else done this and what is their experience? 

Factory the SC clutch only kicks in under certain load conditions; it's not even linked to a ignition triggered relay at all.
 
Usually when you start the car the SC is off, even revving it stationary it's hard to keep the clutch engaged for more than a few seconds, the SC light usually blips and thats it.
 
Having it clutched this way also allows it to be turned off under cruise conditions, so you aren't uncessarily spinning your SC when you don't even need it, saves fuel too.
 
Why not trigger your SC off something like % throttle press?

Why not just change it back to the factory wiring setup.

Maj my sc still behaves as you describe, it engages at a particular throttle and rev combination then stays engaged under load. However the switch distinctly turns the entire system off and allows N/A mode, which is good for economy and gentle driving (warming it up, around town, cruising on highway etc). The wire was traced through a loom, I may have it wrong, sounds like a control unit is between the two, linked to engine ecu. I'm inclined not to mess with it until I get hold of a manual with factory specs. Thanks for the advice.

Do you know if it is a factory pulley on the supercharger?? Some of the other pulleys that get fitted to the supercharger for higher boost (ie the pulleybros kit) run a relay triggered by the factory wires, but run a higher current wire to the to the clutch assembly so it doesn't slip. It could be possible this has been setup with a switch to stop the supercharger from engaging, however that wouldnt cause the battery to go flat if left on.

Hmmm, pretty sure the pulley is stock, home PC died so can't post a picture. This is my first S/C car, so I am a bit ignorant about specs, at first I thought it was centrifugal type clutch with magnetic trigger, not electronically controlled.  :o
 
I actually like having the manual switch, don't really want to change the setup- failing all else I could just install an annoying-as-hell buzzer to make me turn it off, lol.

if the s/c engages like normal from the ECU disconnect the switch wired in and throw it in the bin. 
it's all BS claiming to get better fuel economy etc. by manualy having the s/c switched off.  warming engine up?
the s/c is only going to come on if you give it enough throttle, same with driving around town and on the hi way. 
 
your right foot controls your fuel economy wether the s/c is on or off.  buy a vacuum/boost guage and drive it via that if you want to be real anal about fuel economy.  the s/c aw isn't that bad on fuel anyways.

Yep exactly what feral said.
 
If the car is warming up and the SC is engaging, you need to use less right foot, not switch it off.

Not sure I agree with removing the switch entirely: It has bugger all torque below 3.5k, very slow and lethargic as I would expect from a lower compression 4A. This is just not practical in heavy traffic (or cruising with others).
 
It uses twice as much fuel with the S/C on: On a recent club run, I literally avoided running out of fuel by switching it off, otherwise I would have inconvenienced 8 other drivers by making an early stop, or be forced to abandon the run (how can I keep up without accelerating... seriously?).
 
I am currently on a tight budget, if I remove the switch then that forces me to drive in lethargic torqueless mode 80% of the time. If I must completely alter my driving style and not enjoy the car, then why not just own a crap N/A FWD hatchback, or ride a bicycle instead? I love driving a mild, economic daily which I can switch into an animal on the weekend, this flexibility gives me the best of both worlds, I don't understand why that is a bad thing?
 
No offence, I do respect your opinion and really appreciate the feedback, I just can't see the logic as it applies to my situation?
 
 
 
 
 
 
 
 
 
 

as you said in one of your above posts.. 

This is my first S/C car...

I think you need to learn how to use the loud pedal.  you can accelerate and drive with others and normal traffic with ecu control of the s/c easily with out using any more fuel than trying to manualy activate it.  been there tried that back in 1999.  also there is no way it uses twice the amount of fuel sorry. 
 

It has bugger all torque below 3.5k, very slow and lethargic as I would expect from a lower compression 4A. This is just not practical in heavy traffic (or cruising with others).

I hope this is only how you find it when the switch is off?  if that's how it is with ECU control, then something is wrong.
 
no offence taken. I only say it how I know it.  ;)