Re: 05 secape hybrid not starting
Dont know much about that car but found this on checking , might explain .
" If you leave the key in on position it lets the 300v batt charge the 12v batt."
If your 12v battery is dead, putting the key in the "on" position will do nothing because there's no 12v power available to energize the HV relay and the DC-DC converter. The high voltage cannot pass through the ignition switch, that would be totally unsafe, so a 12v relay is used to cut the HV battery off from the rest of the system when the vehicle is off. Bottom line is that you need some 12v to start the process of charging the battery, and that's what the jumpstart button is supposed to do.
If you still have a little bit of power left in the 12v battery, then yes it might work, but maybe not, depending on just how dead it is."