I want to hardwire/permanently install my LM-1 into my car. However the innovate instructions say this:

"To protect the LM-1 when installed permanently it is a good idea to power the LM-1 only after
the car is started. The starter motor in some vehicles can create voltage spikes of over 100V
that have the potential to do damage. Although rare, this is a real possibility and the LM-1
contains protection circuitry to guard against it. A relay connected as shown below insures that
the LM-1 is disconnected while cranking. This reduces further drain on the car battery by the
sensor heater and protects the LM-1 against abnormally large voltage spikes."

Now i can probably do the relay thing as follows:

"Connect one terminal of the relay switch and relay coil to switched 12V (number 15 on European
cars). Connect the other switch terminal to the 12V input of the LM-1. Connect the other end of
the relay coil to the starter solenoid wire (number 50 on European cars). When the starter
solenoid is operated, the relay will switch off. In running condition, the relay coil current will flow
from 12V through the starter solenoid to ground. The relay coil current is normally far too small to
operate the starter solenoid."

but i was thinking, when you crank the engine the stereo turns off - does this mean that this circuit is already in place in the car and the stereo feed could be used to power the LM-1 without the risk of voltage spikes? or does the stereo simply go off because there isnt enough current when the starter is running?
Im really trying to avoid running MORE wired through the bulkhead and tracing the feed to the starter solenoid etc.......

 

yep your right radio powers off on cranking
Thats how i would do mine mine if i put it in all the time

 

excellent!! - i was thinking it would as otherwise the radio etc would be vulnerable to the same thing as the LM-1 instructions are protecting against. nice one, makes wiring easy!

cheers