Is there a device that allows all of the ECM's values to remain even when the battery dies or is disconnected?
Huh?? The ECM is supplied (on all it's voltage inputs) with 12v battery voltage. It's stepped down internally across zeners to get the needed 5v levels internally. IMHO a 9v battery should suffice on the one input that supplies the static ram chips, only question then would be, would it last long enough.Originally posted by Buick T:
9v might be too much. Most of the bats in industrial controllers use 3.2v lithium that is the same size as a AA.
Problem with that is, you now have introduced a mechanically switched device that depends on the sensing of a loss of voltage to trigger, right?Originally posted by salvageV6:
Why not keep it simple and safe?
Just get a low current relay that switches the ECM load to an alarm gel cel battery, 7-12 AHrs., once power is removed from the relay, meaning the battery dies or is removed.
Feed the gel cel a little alternator current from a wire wound 250 ohm resistor and you're done.
Would be a good way to keep power to an aftermarket alarm as well.