Review on Innovative Metra 70-1786 Radio Wiring Harness for Mercedes 94-04/Landrover 99-04 - Simplify Your Vehicle's Audio System Installation by Randy Montiel

I bought this wiring harness to install a new radio in my 2003 Mercedes SLK 230. This is the right piece! wires (maybe others too). This is a battery constant and ignition. I also installed a SONY stereo. Now the important thing here is that it will depend on the tape recorder whether it turns on without ignition or not. These new stereos are designed not to turn on unless you turn on the ignition, so don't forget to turn off the radio and save your car battery =) I was very confused by this. Of course you can plug in without an ignition wire so it stays on all the time, but I don't mind leaving the key in position 1 while listening to the radio. This is how I know not to forget to turn off the radio. The ignition function is a memory for new radios, so it saves your presets and settings. In addition, the SLK 230 only has two front speakers! (The rear ones are low frequency, they're subs) They designed Mercedes (I don't know why) their amplifier to be such that the front and rear speakers are connected in parallel and the amplifier does all the work - automatically distributing low and high Frequencies to the rear and front speakers. Stupid, isn't it?! I had to read a lot to understand it. So if you take the pinout below, you only need 2 pairs of wires in the middle (left and right speaker), you don't need left and right. Black is negative and color is positive. (This is for the SLK only. My friend had a 4-door sedan and needed everything!). After installation just go to settings and set everything to FRONT or ALL but not back. (You won't hear anything if you put it back =)) Another thing, if you connect via the RCA jacks, you can hear an annoying click every time you play with the menu or turn it on or off. No fear! I simply cut off the RCA connectors and soldered them to the speaker wires on the new radio wiring harness. (Note: Cut the pins off the RCA connectors so you can solder them to your new radio harness and put them back into the plastic harness assembly to keep it looking clean.) No need to cut any of your standard wiring harnesses!