Hey All,
This thread is one of the most helpful threads I've encountered on TS. The info and pictures helped me with a step by step of what to do and how to do it.
I have an 03 HL and had the same intermittent heating issues you all described. Tore the dash apart and discovered the tell-tale frayed wires and knew what I had to do. As a side note, how this is issue not a recall issue for Highlanders? It appears to be a systemic issue.
Anyway, while the dash was a part I was looking at the back of the radio unit and saw that I had an open port (this is normally where a CD changer would be plugged in). I got curious about whether or not I could install a direct line for my ipod and boy did I make a find.
The website
www.mp3yourcar.com will give you mp3 or ipod hook-up options based on the year, make, and model of your vehicle.
I ordered it and as long as I had the dash apart figured I'd install it before putting everything back together.
The only picture I have, unfortunately, is the picture of the finished product.
The ipod hook-up comes with the proper plug to put into the back of your radio, a small box that you install somewhere in the dash, and the wire that will run out to your ipod.
I attached the small converter box to the dashboard frame using Velcro strips and electrical tape.
I drilled a small hole in the inside bottom corner of the center console.
(note: Remove the rear-seat ash tray on the back side of the center console to have access to drill from both sides of the console wall.)
I then used a fish tape to feed the wire from the back side of the center console, all the way up through the center console (it will pass right by the cup holders) and up into the gaping hole in the dashboard that you'll have while the heater and radio unit are out.
My ipod plays through the radio with CD like quality and charges at the same time. The ipod charges through the radio and there is no splicing or taping of wires required!
Follow the instructions and you'll be good to go.
Good Luck and Enjoy!