I just bought a 70-8113 wiring harness for my car. I installed it and wanted to run it through a quick test so I grabbed an RCA to 2.5mm jack and my laptop and went out to my car. (The ones used for surround sound on PC's) I plugged it in and started playing music, as it was playing I plugged the headphone jack in and.... nothing. I was a little concerned about this but my dad said it was because I didnt have my amp hooked up and the little laptop wasnt pushing enough power to hear any thing through the speakers. I would think that no matter what you would hear some thing very faint if nothing else? Any one know if this is normal and if thats right? Thanks a lot.