2004 jetta radio install question...

I removed the factory radio, got a wire harness to match, ready to do the install and noticed the red hot wire is missing from the aftermarket harness that attaches to the factory harness. i did some online searches to see how to bypass this and people are saying to run a wire to the fuse box. Couldn’t I just cut the red wire from the factory harness and attach to the red wire from the aftermarket radio? or will this throw communications off to the radio? If I run a wire to the fuse box, where should I hook this thing up to? The cigarette lighter is always constant even with the keys out so that option is out. I thought I had a pretty good handle on this but seems I do not! Any suggestions dudes? Thanks…

You do have to run a wire to either the fuse box or the ignition harness, I recommend the fuse box. If I remember correctly, you can use the same fuse as the wipers as they are switched unlike the lighter.