Installing an Aftermarket Head Unit
Aftermarket Head Unit (this one is a Clarion DXZ545MP)
Metra Harness #70-1761 (fits all Toyotas from 1987 and up)
Metra compartment box (if you have a free DIN slot you need to fill up)
Tools & Supplies
Philips head screwdriver
Soldering Iron and Rosin-core solder
Heat Shrink tubing
Heat gun, matches or lighter
P-touch label maker (optional)
18-gauge power (Red) wire
Alligator clips (2)
I am providing this write up for illustrative purposes only. Perform at your own risk. Any mods (including this one) you perform on your vehicle is your responsibility. Commercial use of this write up will result in legal action as well as the undying scorn from members of the online Toyota 4Runner community. You've been warned.
This writeup is based on the assumption that you have a stock Toyota stereo installed in your vehicle and you are installing a Clarion DXZ545MP head unit only (no amps) to four stock speakers. Also throughout this writeup, I'll be interchangeably referring to my new Clarion head unit, "new head unit", and my old, stock Toyota head unit. Please keep that in mind when reading this writeup.
So my learning experience began when I decided that I wanted to get a new head unit to replace my stock one primarily because I wanted a head unit that had MP3 playing capability. Thus, I purchased a Clarion DXZ545MP, a quality, moderately priced and full-featured head unit that fit my budget and needs. Now selecting a head unit was the easy part. Wiring it up without the plug-and-play Crutchfield harness was another!
I'm a total novice to stereo systems and how they work. Special thanks to DavidA who answered several of my newbie emails and went above and beyond with recommendations on equipment and where to buy it. Thanks, David! Also, Cebby provided me with another great piece of advice for any car stereo/electrical work you do: do NOT use a Test Light. Use a multimeter if you are trying to probe voltage for any wires. Using a test light may cause weird things to "trigger", up to and including deployment of your air bag. Here is an additional warning (verbatim) from one of my favorite websites on anything car audio electric, "Basic Car Audio Electronics":
"If you're not probing anything other than the wires going into the radio or the amplifier, the test light is safe. If you're testing the voltage in any other connector under the dash, you absolutely MUST use a digital multimeter."
Ok with that, read on and take note of the little details that will make this job a lot easier.
Also next to politics and religion, nothing stirs up more passion (and needless internet drama) than car audio. Personally, I don't give a rat's ass if your stereo can kill mine, or that I should've bought this and that because "its the best." I am not interested in hearing about it. This article is older than dirt now, but the wiring and approach is still the same with new equipment too. But again, if there is something that is incorrect, that is the feedback that I'd like to hear.
Step 1: RTFM (Read the Bleepin' Manual)
First off, the process itself is very simple. However, getting the right results the very first time takes patience and planning. This is especially important if this is your first time wiring a harness together because you have many wires that need to be soldered. So take your time and get it right the first time. And as always, read your stereo's installation manual a few times to get yourself familiar with your stereo's wiring schematics. Once you familiarize yourself with it, review your Mertra harness wiring color chart too.
For the map above and from left to right, your stereo will be connected by a series of harnesses. My Clarion stereo came with a harness (SH) which has the plug harness at one end and the loose wires at the other. To mate these wires, I purchased a Metra Harness #70-1761 which comes with two harnesses. You need to solder the Metra harness wires to the Clarion harness wires. This will allow you to plug your Metra harness into your 4Runner's stock harness.
After labeling all the wires, do a test matching of the Clarion and Metra wires. Of note, the Metra purple wires are almost black in color. It is especially difficult is to pick out the purple/black wires. Thus, look under a very bright light and determine which one is positive and negative.
Here, pay attention to Steps 1 and 2. In Step 2, you really only need to do Figure 10, 11, and 12. Step 3 is not relevant. One step that is not included is putting on a piece of heat shrink tubing on the wire before soldering. Once the solder has set, move the heat shrink tubing above the soldered joint and then shrink with heat from a match or lighter. See my labeling and soldering work below:
Step 3: Removing Radio Panel Fascia
There are three pesky philips head screws that securely fasten the radio panel fascia to your 4Runner. Remove those screws. Now you are ready to lift out the radio panel fascia itself. Begin by grabbing it from the bottom and pulling upwards and outwards. The radio panel fascia is clipped at the top. Once lifted out of place, remove the three harnesses located on the upper driver's side (hazard, clock and rear defroster). Continue by unfastening the bottom ashtray light (twist and pull out) and the cigarette lighter harness (unplug). Finish by moving this big hunk of plastic out of the way.
Step 4: Removing the Stereo and Amplifier
There are total of four screw bolts holding the stereo's "cage" onto your 4Runner. Remove those screw bolts and gently pull the entire unit out. There is a single harness coming from the amp that is attached to the back of the stereo as well as the power antenna plug and the power plug to the stereo. Remove everything and then pull out your caged stereo. Next, unscrew the two screws that are securing the amp to your 4Runner. Pull that out as well and unplug the two harnesses behind it.
Step 5: Out With The Old, In With The New
Also, you won't need the metal cage that most aftermarket stereos come with nor the plastic trim ring for perfect fitment in your 4Runner. Remove both before screwing in your new stereo.
Plug in your new stereo's harness kit into the back of your stereo. Then connect your Metra harnesses into both the stereo's harness kit and to your 4Runner's harnesses. Plug in your antenna and power plugs into the back of your stereo. Now you are ready to power it up for a test run.
Reattach all the radio panel fascia pieces in reverse order. Here's a pic of it installed in the 4Runner with the Metra empty DIN storage compartment beneath. Of note, I found this Metra pocket utterly useless for keeping things inside without it spilling out on even moderately sloped hills. Find one that slides out like a dresser drawer.