Magnetic field put off by high current (causing cross-talk between wires)

[Tesladude]

Ok so I haven't been on here for a while but I can't seem to find an answer to my question anywhere and really need some help!

So I not only am an electronics hobbies but I have fun installing car audio systems as well. The problem I am running into is that I would like to run an alt wire through my engine bay that would be zip tied to the same leads giving signal to my injectors and ignition coils, this 1/0 wire will be carrying at times over 200A and will be mere millimeters from these signal wires. I am worried that the magnetic field put off will in turn cause interference to my vehicles electricals given that they are at such close proximity.

BUT!

After looking through my engine bay I found that the stock alt wire is literally in the same loom as the signal wires I am worried about. So I imagine it would be fine but I need to know for sure.

Would the magnetic field of 200A through 1/0 fire interfere with ignition coils or injectors only millimeters away?
I appreciate any help! :)

 

[jrmichler]

The wires to your injectors are carrying relatively high current (amperes) in a low impedance (double digit ohms) circuit, so they are resistant to cross talk. Cross talk is a problem with low currents (microamperes) in high impedance (megohms) circuits at high frequencies (100's of kiloHertz and up). The high voltage from coils to spark plugs also causes problems because it is high frequency (actually fast rise time) and high current. I suspect that is a reason why modern automotive technology puts ignition coils on or very close to the spark plugs and does the switching on the low voltage side.

 

[Tesladude]

Ok that makes sence, even if any voltage is generated in my coil harness or injector harness it will be very small and not offer enough current to actually do anything?