I finished rerouting the plug for my auxiliary jack and connecting my computer audio which needed a power inverter to power the computer, I turn everything on and I was getting a nasty hum that wasbeing created from the power inverter passing crosstalk into the Auxcable. I tired different shielded 3.5 mm plugs but I was getting the same effect.. I found a solution that I have used in the past and wanted to share the concept with you in case anyone runs into a hum using the aux cable with their audio equipment as it works nearly every time.

It has been my experience that 90% of speaker/radio hum issues are related to grounding issues so I took a 3.5 mm male/male cable and cut one end off of it,removed the plastic and metal shielding off about an inch, to reveal the 3 wires that make up the cable (Usually red, white and an exposed copper ground/audio - return) I cut off the red and white wires and taped them so they wouldn't touch later.
I then attached an eye terminal to the end of the copper ground wire.

I lifted up the carpet on the passenger side to reveal a support beam inside the car which I took a dremel and ground off the paint in a 1/2" circle (To make a better ground connection) and then used a self tapping screw to attach the eye terminal to the exposed metal.

I then plugged a 3.5 mm 2 way splitter into the extended aux cable which including the previous splitter gave me 3 aux outputs in which I plugged the computer audio out, the iPod audio out and the new 3.5mm grounding wire I just created.

The hum immediately went away due to the addition of the grounding cable.

I don't expect too many people to haveissues with hum since most people aren't using inverters with their aux electronic audio equipment.. But if you start adding stuff and do get a hum try this out as it will surely fix your problem and it's a relitively easy fix.

 

That's great you included this about the hum for people that are doing what you're doing. There maybe someone who needs the help.