I meant BATTERY voltage, i.e. measured at the battery

I can see that the fusible links are a likely cause of the drop to the ECU, thing is, this ECU voltage is only about 0.5V less than battery. I repaired them last year, but I'm thinking that your way might be a useful mod

I've run a jump lead from the alternator to the battery positive tonight, this didnt affect the voltage at all. I can't see how the battery voltage is so far down from the alternator voltage

The only way I can imagine it is that the rest of the vehicle electrics are dropping the voltage at the battery, or that the battery is poor...

Cheers for the input Chip

Neil.