I know similar questions have been asked before, but I haven't seen an answer anywhere - going to splice into the light switch wiring for my boost gauge, its mechanical so only need to connect a switched live and earth.

I'm going to connect into the wiring behind the light switch, but don't have a multimeter to hand. Can anyone that has already done this tell me which wire is the switched live? And is there a good earthing point somewhere behind there?

I have heard people saying about using the fusebox or relay board to tap into for a feed - whats involved in this? Exactly how would you use an empty fuse slot?

Ta

Andy

Hi, there is a relay under the drivers kick panel which Is marked 75x. This is switched live. There is a nut on it so you don't have to splice any wires, just fit a ring connector on the wire from the boost gauge:thumbup:

If you want it to light up with the instruments only - try wrapping it around the parking light fuse terminal on one side and replacing the fuse....

I have to appologise. I have misread the question like a plonker:rolleyes:

Ignore the relay solution as that is a switched power source in conjuntion with the ignition switch & will be no good for the illumination of the gauge. On mine I have linked into the sidelight wire behind the light switch.

Which colour is the sidelight wire?

Which colour is the sidelight wire?

The wire I tapped into behind the light switch was grey/purple. you could also tap into the grey/brown wire.

As these wires are before the fuse box I connected at the back of my gauges a blade inline fuse holder with a 5amp fuse for precautions. The holders are only pence from halfords & is a piece of mind.