just need a quick confirmation before I tackle the project. I will be replacing the HU with a Kenwood very soon. I ordered the Kenwood from Crutchfield. The tech guy there had told me that I actually do not need to disconnect the battery for this replacement as I am simply reconnecting the stereo harness. Is he correct or am I risking possible electrical damage to the stereo or the rest of the car's electronics? If I do need to disconnect, it is the ground wire/cable to the car's chassis I disconnect, or the negative post of the 12v battery?
I didn't when I did my install. When I was finished however I had a nasty message come on the HSI (can't remember exactly what it said now). Fortunately all I had to do was cycle the car on/off three times and the message went away. It really freaked me out though. With that said, I would disconnect just in case.
You will need to disconnect the "gearshift" panel minimally, so you can experience some display messages or ECUs MIL codes when battery is connected. If you disconnect the battery ground you are on safe side.
I've swapped out stereos 4 times now without disconnecting the battery. Had one issue - powered it back up to check the install - but forgot to connect the center panel (removed for install). Got an error message that went away once I connected the center console. All Toyota manuals will state "disconnect the battery". I've had seats removed (adding leather 2 times) etc. Personally I think is a monstrous PAIN IN THE ... to disconnect the battery. I can literally swap out my HU in less than half the time it takes to disconnect the battery (all things equal - disconnect, reconnect - due to all the stuff I have to pull out of my car...)
Just finished the HU install. Kenwood sounds phenomenal. The equalizer helps tremendously on the bass. Got stuck a few times. Dropped the stereo chassis screw into the abyss behind the panel. Spent almost an hour retrieving two of them. For any future installers I would strongly recommend stuffing some double-sided tape in the inside of the socket wrench where it contacts the screw so it won't fall as you're removing/tightening it. Another key thing that people ought to do is to tape a temporary protective cover(paper or cardboard) over the HVAC display. It got scratched up pretty bad while I was removing all the trim. The shifter should also be protected. I just threw a latex glove over it and that worked just fine. I ended up disconnecting the battery, at the point where it is secured to the chassis. The manual had strongly discouraged that as the loose cable end may accidentally contact the positive terminal and cause a possible short. I just threw a leather glove over that to isolate it. I picked up a 6x9 speaker at BB just to see how the fit was. The cutout was fine, but it was too deep. The magnet protruded too much in the back. It probably would hit the window glass as it rolled down. I saw a Sony 5x7 and picked that up. Will see if that may fit and compare the sound to a 6.5" l
