Hi Everyone,
Electric question - headlight turning "ON" as soon as ignition key is "ON". I want to keep it "OFF" until engine runs
I have been playing with my electronic and realized that everything is pretty simple. Since the Arduino can be programmed in C and all I am trying to do is very trivial, I start to wonder why the M-Unit is so expensive. But still, there is one feature of the M-Unit that I don't yet understand how it is done. I have few work around but none are perfect.
When I turn the ignition key on, the headlight come on. This, to me always been a bit of strange as you want to use as less as possible you battery until the alternator takes over when the engine is running(sure they are not planning for you to have issue starting the engine and thus, this discussion become a bit of a moot point).
For those of you who played with the electronic. Is there a signal that we can "sense" that tells us the engine is now running ? I have few work around:
- Sensing the oil pressure light (as it turns off as soon as the engine runs)
- Adding a fix delay between the "Turn key ON" and "Turn lights ON"
- Sensing when the alternator produce more than the 12V from the battery. (So headlight would stay off until you rev the engine for the first time)
- Seen some induction reading done over the coil wire. ( used to do an electronic Tach read out)
- Adding an extra switch to turn the headlight ON
All of the above should work, but none are perfect. Any of you knows, or have done similar thing to keep the headlight off until the engine is running ?
thnx
