Electrics question

[IMIX]

Greetings!
firstly, I want to thank everyone here IMMENSLY for the vast amount of knowledge and passion for this bike.
I bought my XS1100SF this last august with 13.5k miles on it, garage kept, awesome shape.
falsely, the PO fancied himself an electrician, and had no sense of style.
so with the help of this site, and ebay, I have it working and street legal, cleaned up, and she is AWESOME!!! (no name for her yet)
this is my first bike, its a hellova machine!!

So, what i'm doing, is programming a pic processor to take in voltage, current, oil temperature and pressure readings, and display them to a nice OLED display with a clock and compass.
see, I'm an electronics geek, and have access to this stuff, and well, idle minds.....

my questions are:
1. where should i insert a shunt resistor to take the current reading?
off the regulator? off the main 30A fuse? (looks like thats just for the battery tho?)
I don't know a better way of getting a current reading, I have a .2 ohm 1% power resistor.

2. what is a normal current draw for this bike?
an approximate breakdown of headlamp, brakelight, signal lamp draw or whatever would be great.


3. is the best place to take a voltage reading at the battery, or off the regulator? difference?


I'm a complete newb when it comes to motorcycle and automotive systems, I've learned more in the past few months from getting this bike working than in my whole life. its great!!


Thanks again everyone!!!
~Eric

[DiverRay]

Eric;
You will want to take the voltage off the battery, and the current off the regulator. Put your resistor on the line between the reg. and the battery, and it will let you know if the reg/gen unit quits. Voltage across the battery will show the "state of charge" and let you know if you are pulling more power than you generate. This is a known weak point of this bike.
The power draw of the bulbs can be computed using ohms law. Assume 13 Volts, 55 watt low beam and that is 4.3 Amps.
W/V=A Stop lights and turn signals use about 27 watts, running lights are about 15 watts. Bulbs can vairy, but this should get you going.
I'm not putting on the goodies you are, but I'm a HAM radio operator and plan on installing a mobil on my 1100!! I also work with computers and chips for money, so I can ride and play in the water on weekends!!

[IMIX]

Thanks DiverRay!
do you mean put the shunt resistor on the red line between the reg and the battery?
its the only wire that connects the two directly.
if so, that IS the one that has the 30A main fuse inline and would be an easy install.
Will that give current readings when i turn on/off the signal lamps, horn etc?
it looks like the brown wire would give me that reading...
(still working on the whole mental picture of signal flow for this thing)

lawdy thats a bunch of current for a couple of lights...
I may end up installing some of those LED repacement kits too.
mmmmm..... SS brake lines first tho....

[TopCatGr58]

Hey there IMIX,

The Solid Red one is the main power line, which runs thru the keyed ignition switch, back to the fuse block via the gold/brown wires, where they then run thru the fuses, for lights, ignition and such. Only during startup, there's a red/white tap off the battery cable that goes directly to the coils bypassing the ballast resistor to provide stronger spark for start, but isn't used once the engine starts.

It's been estimated that the ignition system draws about 10amps, but not been confirmed/documented officially? Yeah, the lights do draw quite a bit, especially the turn signals, but also the dual bulb brakes, and headlight if you're running stronger than stock, so that's why I did the LED switch. Would be nice to hear some actual values on current draw both before and after your LED conversion!
T.C.

[randy]

10 amps is about right for the ignition system. The coils draw 4 amps apiece and toss in a couple of amps for the TCI.

[IMIX]

Thanks for the replies!
for anyone interested, Here's a huge color schematic for an SF.
(an accurate one, not the one in the color clymer)
That site also has nice big color wiring diagrams for an E, G, and SG as well.
(gotta love google image search)
I will do some tests over the next few weeks,
and eventually post some pics and stuff when i get things figured out.
Thanks again!
~E