When I was inspecting my engine bay I notice there was a plug not connected to anything (as well as the fuel pump relay just dangling ), it ran on top of along the cam cover. I think its the a/c magnetic clutch connector according to the bgb. I think its been left unplugged since i got the car, what are the effects of leaving it unplugged? I only just recently replaced my a/c amp and got air conditioning working finally after 5 years of owning the car. I've been reading up on a/c clutches but am a little confused, if its purpose it to engage and disengage the compressor while engine is running how does my a/c work if the plug is unplugged?

You've got the function of the a/c clutch dead right.  If it wasn't connected, it won't engage and the system won't pump.  First thoughts are you've got to answers coming . . .
 
Firstly, it's NOT the A/c connector and your system is all happy happy joy joy
Secondly, it IS the A/c connector, and your pump clutch is jammed, so the system is pumping continuously.  This is relatively easy to check - loosen off the aircon belt, and see how easily the aircon pump pulley can spin.  If it seems to drag, or you can feel a "pulsing" through the pulley, I'd be looking at the clutch itself.
 
Can you see the colour of the wires going into the connector?

Is your car turbo
There are 4 plugs there.
O2 sensor
Ic fan
Ac
cat temp sensor, will be unplugged if you have a aftermarket dump pipe

Car is turbo and has an aftermarket dump pipe, the plugs for the o2 and IC fan are accounted for, then there's one with black/white wire connected going all the way down, I assume that's the cat temp, so the remaining one must be the a/c mag clutch. However its not long enough to plug in. There are two wires for that plug,they look faded but it looks like 1 red and 1 pink.
 

Whoa silly me, looks like the black/white wire IS the a/c clutch (makes more sense now when reffering to the wiring diagram, wire colours didn't match up) its just the the plug broke of the mounting bracket, so i thought it was left unconnected. But anyway, any idea what the plug in the in the above post is?