Hi,

We are in the middle of trying to work out the wiring on our 3/4 built MK indy we bought. All looms are in but not connected to anything.

So we've got the ignition + starting circuit workin so next thing is fuel pump.

The looms are 'premier for sierra based cars'. Now according to the sheet from them, the fuel pump should be on a 15A fuse, with a black/yellow wire. I can find this on the fuse box - a black yellow coming from ignition barrel that switches on in the 2nd position.
However the other side of this fuse is a black/purple - not what I'd have expected? The black/purple then joins with a whole load of black/purples.

Then to confuse things further the sierra haynes seems to suggest the fuel pump is on a 20A fuse and black/red wiring!?

Also, no mention in the premier guide of a fuel pump relay?

Are there any diagrams available? trying to decifer between the premier guide (which is minimal imo, 1 sheet of A3) and the sierra manual isn't easy.]

Any help on this much appreciated. In theory it may be start-able once we've nailed the fuel pump

If I remember correctly, Black is the colour that ford use for ignition controled live feeds that ARE switched by the ignition switch, the trace colouring in the wiring is very much changeable. If you take a complete Sierra or Granada loom and strip off ALL the insulating tape/material you will understand what I mean.
IIRC - - - - -
Red is a permanent live.
Black is a switch live (ignition on).
Yellow (switched live & Aux switched live).


Hope this helps.

Thanks for the reply.

Problem is though (the way I see it in my mechanical non-electrical mind) if I use one wire that I think is right, but then later down the line I find was meant for something else?

I suppose this only matters if trying to rigidly stick to a colour system or standard. As long as the feed I choose goes live at the right time and uses the right fuse then perhaps I shouldnt worry? Is this how others wire their cars? I suppose as long as you know yourself what you have done it perhaps isnt important - apart from the poor sod who buys it off you? lol.

But what about a relay?

I did it (as some might say) the hard way, took the complete Granada Wiring loom (2.0i pinto) and thinned it down as required. It took a fair bit of work with a haynes manual wiring diagram to do it but the end result I think was worth it.