On my Sierra ignition, the wire coming out of the ignition that I call Crank (the wire that has continuity when the key is turned to start) is a pretty thick cable say maybe 3-4mm in diameter. The cable on my wiring loom that goes to the starter solinoid is 1.5mm thick. Surely all this cable does is send a small current to the starter solinoid which then connects the big main battery cables. So why is the output on the ignition barrel so thick?????

I don't like connecting 1.5mm cables to 3-4mm cables - makes me think I have made a mistake.

Thanks

Mine is/was the same, but the wire to the starter is much thinner so I think that within the loom it must be reduced down. I used the ford loom to run my car, just with the extranious wires removed, (electric window etc). HTH Ray

FYI, the RV8 engine on an SD1 at least, has a starter solenoid relay. So ignition switch drives relay which in turn drives solenoid. This suggests the solenoid takes more current than the SD1 ignition switch can reliably handle. The sierra switch may be designed to drive the sierra solenoid directly but I don't know if the sierra solenoid needs as much current as the SD1 solenoid. I'd fit a relay to be safe.

Hth,
Craig.