Arduino to control relays for motorcycle turn signals?

Hello all, I was wondering if I could shoot this idea by you and see if its solid or trash.

Im rebuilding a bike that had a hack job of wiring done to it in the past 37 years of its life. All sorts of terrible electric tape jobs and glue and crusty rusty spin caps wound down around it.
Ive heard that the bike puts out about 150 watts of power. Fully fairinged and saddle/trunk bagged it ran 4 speakers, 7 incandescent light bulbs, a ye olde head lamp, and a radio with (I guess) no problem. Id like to cut out 6 of those incandescents, update the speakers, update the radio (maybe make it able to play tape cassettes …just kidding) and possibly add an amplifier, heated gear, yada yada yada.

I am not very learned on the technical terms, nor am I adept at arduino coding. I do know I dont want to use the delay funtion. I have been playing with an arduino uno and some leds :slight_smile:

The Idea:
To start though, Id like to convert the 6 turn signals/running lights over to arduino control.

I want the arduino to be run on the head lamp circuit of the bike, which when the starter button is pressed, the circuit is killed to divert all power to the starter motor.

The arduino will be powered from a DC buck converter using and LM2596 deal, the module, not the single lm2596 itself.

I want the arduino to communicate with 2 relays and have the relays bridged all the time. Each relay will power, at 12v, 24 white LEDs, 12 in the front and 12 in the rear.
The reason I want to arduino to send a constant signal to bridge the relay is so that the LEDs act as running lights.
When I send a signal (flip the turn signal switch) to the arduino, I want it to turn off the appropriate sides relay, then wait lets say 500ms and turn back on, and off again on repeat. This leaves the other side lit and the selected side blinking.

According to ledcalc.com it says I need resistors (which is fine) to get the max brightness out of the leds without burning them.

Another reason I want to use relays is because I dont want to try and supply 48 leds via pwm through the arduino.
Ive considered pulse width modulation, but honestly, I want to be SEEN at all times. Im going to use custom cast amber and red front and rear lens covers on the leds, which is why I want them white. Longer wavelengths right? Easier to be seen during daylight hours?

As my bike is now, it does not have the ability to do 4-way flashers. Id like to run that too.

Space to keep the arduino and the module isnt a problem. I have an empty tool compartment in a cool dry place under the seat and behind a cover, so the the stuff will get cool air but also remain dry (probably going to make a watertight box)

Id like to run an arduino not just to do led signals, but in the future other things like monitor the bikes charging system, utilize the speakers to buzz at me if the temperature is getting too hot, etc.

Thank you for your time!

Hi basimpo, see my PM for ideas.