wireing in fuel pomps

[321gazza]

Would like to fit a switch between the fuel pump relay and the fuel pump can i do this on my 318i, if so what amp fuse should i use if at all. Also would like to do the same on my track car using a bosch 044 pump but with a simple on/off relay fuse and switch.

[Brianmoooore]

Pick up the green/purple pump wire where it comes into the cabin behind the glovebox, and goes down to the sill behind the front of the speaker cover panel. Already down wind of fuse #11 at this point, so no extra fusing required.
If this is for security on the road car, I'd advise connecting a wire to the pump wire, without cutting it, connecting that wire to the switch, and the other wire from the switch to earth (stud behind the glovebox).
If anyone tries to crank the engine with the switch on, fuse #11 will immediately blow, making the engine impossible to start if they subsequently find the switch, or making a simple hot wire to the pump also fail if the switch isn't discovered.
Probably not a good idea to do this on a track car though.

[321gazza]

Yes its for security, but the engine has its own loom not using any wires from my e30 so will be wiring it all by its self ie custom loom just for the fuel pump, using relay, fuses, switches and i'm not an electrition.

[321gazza]

Can i run two pumps off of one relay and fit a switch to one of the pumps to turn it off/on as i wish.

[Brianmoooore]

You can, but ideally they should be individually fused (although BMW didn't bother with early two pump cars!)