Arduino to control 12v circuits

Hello all. I am wondering if I can use an Arduino to control a 12v can bus circuit. I need it to work like a 12v relay allowing power to pass through, when I activate the secondary circuit I need the relay to open, and send the 12v power the truck would be passing through the relay to a 6 ohm resistor hooked to ground as to "trick" the vehicle into thinking the canbus circuit is under load and reporting back to its controller. Is there a simple way to do this that doesn't cost much? I have the setup hard wired but it would be nice to have a simpler setup, I am also thinking about a second switching setup that could turn off the vehicle traction control. I'm 100% new to even the idea of this I've never dealt with any computer stuff like this. I am very good with wiring though automotive mechanic for 10 years as a wiring specialist. Thanks in advance.

As digital devices Arduinos work well for switching. They TTL (Transistor to transistor logic) voltage and current levels. Thus any circuit will involve the Arduino driving transistors that can handle voltage the are required to operate the relay. I would start with the Arduino driving optocoupler, which both isolates the Arduino from the rest of the circuit's noise and can step the TTL voltage up to 12V so you can avoid logic level switching transistors. Discrete MOSField Effect Transistors will handle your relay's power needs. They come in many flavors and are superior to power transistors.

So as I see it you need these functions

Relay closed state Change state of a Arduino input pin Read input pin state (switch) If pin state changed (say goes from HIGH to LOW) Change state of a Arduino output pin 0.30 amp, 5V signal closes the

I need it to work like a 12v relay allowing power to pass through, when I activate the secondary circuit I need the relay to open, and send the 12v power the truck would be passing through the relay to a 6 ohm resistor hooked to ground as to "trick" the vehicle into thinking the canbus circuit is under load and reporting back to its controller. Is there a simple way to do this that doesn't cost much? I have the setup hard wired but it would be nice to have a simpler setup, I am also thinking about a second switching setup that could turn off the vehicle traction control.

GeoAC: As digital devices Arduinos work well for switching. They TTL (Transistor to transistor logic) voltage and current levels. Thus any circuit will involve the Arduino driving transistors that can handle voltage the are required to operate the relay. I would start with the Arduino driving optocoupler, which both isolates the Arduino from the rest of the circuit's noise and can step the TTL voltage up to 12V so you can avoid logic level switching transistors. Discrete MOSField Effect Transistors will handle your relay's power needs. They come in many flavors and are superior to power transistors.

So as I see it you need these functions

Relay in closed state Change state of a Arduino input pin (throw switch) Read input pin state (switch state) If pin state changed (say goes from HIGH to LOW) Change state of a Arduino output pin (0.30 amp, 5V signal closes the optocoupler and 12V is fed to the MOSFET that in turn opens the relay.) Relay in open state

Cost under $10.

For code example start with :https://www.arduino.cc/en/tutorial/blink