Well there is this whole thread:
You'l see "TeeRiver" did a different version of this (far prettier haha).
Pulled from SV Gear Indicator. | Page 2 | Suzuki SV650 Riders Forum
Inside the ECM is a 1k resistor pulled up to 5v. If the 1k internal ECM resistor is proper, then a 1k ohm external load will voltage divide 5v down to 2.5v. If you don't see 2.5v then start looking for a series resistor inserted somewhere on the Pink wire to the ECM.
You can also test the gear position sensor resistors individually by disconnecting the sensor, then measure resistance between sensor Pink, and ground Black/White. Should see:
1st: 374 ohms
2nd: 547
3rd: 1k
4th: 1.82k
5th: 4.6k
6th: 10k
N: open circuit.
FYI- there aren't any extra resistors inline here I've checked, just the 1k in the ECM and then the list above.
Perhaps there is a way to calculate this?
I'll give some readings:
| With Arduino Connected | Without Arduino Connected | |
|---|---|---|
| 1 | 1.34 | 1.36 |
| 2 | 1.81 | 1.76 |
| 3 | 2.48 | 2.57 |
| 4 | 3.22 | 3.23 |
| 5 | 3.75 | 4.11 |
| 6 | 3.84 | 4.52 |
| Neutral | 3.89 | 4.97 |
All of this said- I reprogrammed the arudino to look at the "On and Plugged in" numbers- that is the closest I got - but it displays 3 for First gear, 4 for 2nd gear, and N (Neutral) for all the rest... as if it is STILL not seeing the same voltage my multimeter is reading.
My old laptop isn't working with a batter- im half inclined to setup the duino with a LCD and have it print voltage readings and then just program for those numbers....
As for transistors and resistors... I have a bunch of resistors- this whole kit http://www.amazon.com/Arduino-Sidekick-Basic-Kit-Version/dp/B007B14HM8/ref=sr_1_1?ie=UTF8&qid=1367321842&sr=8-1&keywords=arduino+sidekick
And a few other things laying around. Again- really wasn't anticipating a complicated project.