@dbvanhornOuch, that sounds like a serious flaw, I'm a noob to circuits (glad I got sofar and I tried searching for the components on digikey but I couldn't find what you mentioned, any help for me there?
I don't think any of the component sites allow searching for automotive-rated components, but you can just google for "linear regulator automotive" and get tons of hits on manufacturer sites.The DE-SW050 is a switching regulator; while it'd be much more efficient than a linear regulator it's pretty pricy and really not warranted here with the low currents you'll be seeing.Add a decoupling capacitor to your multiplexer IC.To create a ground plane in Eagle use the polygon tool; draw a rectangle along the edge of the board. Right-click on the line and set the name to "GND". It won't look like it's filled in but you can click "ratsnest" to make it visible or of course you can look at the resulting files with a Gerber viewer after running the CAM processor.Did you verify the amperage requirements of the coil of your relays that they are under 40ma? If not you'll need a transistor.
I already have the DE-SW050 laying around, catching dust. Al through its not really warranted, it handles the job right? it also saves me from soldering more components to my breakout board
I quickly made a new schematic for the breakout board. Did I placed the capacitors correctly like you meant to?
You might contact DimensionEngineering and ask if the regulator is suitable for use on a motorcycle. Aside from crossing your fingers and hoping it works it'd be the best way to find out. Also, since you seem to have enough space on the board, it wouldn't hurt to add a couple places for caps on both sides of that regulator as if you were using a typical linear regulator. You've got a fall back position then.
Yes. Try to keep those caps as close to the IC as possible. Again after testing your board you might not find them necessary ... but you've got that fallback position.