sc12 magnetic clutch not engaging

[NZAE92]

Hey
A friend of mine has a Hillman hunter with a sc12 2tgeu in it.
i know it's not relevant the car and the engine to this forum but just here me out.

Ok, so the supercharger was working fine before he moved the relay,
now the magnetic clutch inside the supercharger is not engaging.

Can anybody give me some information why the magnetic clutch may not be working.
All the voltages are fine, he has checked the relay and that is fine too.
so we are both stumped.

sorry again for the irrelevant engine and car but this is the only place that i know that can supply me with sufficient help and information.

Thanks
Greg

[Blof-fan]

Stupid question perhaps, but is he sure he wired the relay correctly again?

[canadianae92]

so you read 12v from the mag clutch's input?
and like blof-fan said. If the relay isn't hooked up right then it won't work right for sure

make sure its grounded well(it should be grounded through the sc housing though), and jumper 12v power right to it and see if it engages, if it doesn't some internal contacts might be worn out or an open inside the unit

if it worked fine before it is likely a fault in wiring, with a voltmeter you should have a 0v measurement from battery positive to the mag clutch power input, if you read 12v you have an open or anything really might indicate a poor connection(keep in mind this is with the relay energized, if the relay isn't energized you'll read open(12v drop))

i dont know the specifics on the sc12/mag clutch but hopefully this helps

[NZAE92]

This is what my mate told me.

There is 12 volts at the supercharger when the relay is engaged and ignition is on.

It has an adequate grounding from the casing to the chassis rail which is connected to the battery at the back. Best connection possible.
When the relay is off no 12v is at the super charger.
Relay has been wired corectly for sure and there is no voltage drop across the wires and it is not grounded through the case, it has a seperate wire.

The relay is done correctly as it has a plug onto the relay, not just random wires connected to it, so it cannot be wrong.

Cheers
Greg

[canadianae92]

ok so its either a bad ground(which by the sounds it shouldn't be) or an open/bad connection/internal problem with the magnetic clutch.... could be a internal wire broke or something... there's a big coil of wire inside that's used to create the magnetic field used to engage... before taking it apart i would double check the ground.... the winding for the magnetic clutch isn't really repairable if that is the problem....