A while ago my Range Rover (2007 SC) wouldn’t start. I tested the battery and it was OK, but tried a jump from a booster and still no joy.

Called the AA out and he did the same - check battery, jump start on battery and tested the earth at the engine. All OK and still no start. He said it was probably the starter motor or ECU and he wasn’t able to check those on the roadside.

I wasn’t convinced it was the starter so tested the voltage at the main battery wire at the starter and all OK. Then I ran a direct wire from the battery to the small connector on the starter motor and with the ignition on the car started. So the starter motor is OK.

I got a new ignition switch and tried that - still no start (and what a pig that is to get to!).
Changed the starter relay - still not starting on the key.

So I have rigged up a button to start the car; running from a fuse in the fuse box to a switch and from the switch to the starter. I did want to run my wire from the ignition switch to the starter in case it was just the wiring, but I couldn’t get any voltage at the ignition switch when the key was turned.

Now it’s starts OK every time, but I really want to get this sorted and repaired properly.

It must be the wiring or electronics somewhere, but I’m out of ideas. Could it be the ECU or some other trickery?

Does anyone have any ideas for me to try?

Thanks 2007 4.2 Supercharged
2006 3.0 V6 Jaguar X-Type
1993 Toyota Corolla 1.8 GXi
1971 Triumph TR6