March 28, 201214 yr Hello all, I'm finally taking care of the dash light problem on my '93 Legacy that I created by putting in a new radio and fancy under-the-seat subwoofer without consideration of the infamous illumination control module. I had hooked up the radio's power-from-ignition wire to the yellow/red wire (from fuse #17) on the Legacy. I hooked up the radio's constant 12V lead to the Legacy's blue/red wire (from fuse #25). From reading the posts about such things, it sounds like I should avoid using those two wires altogether. So, without having to go through all those wiring diagrams with my feeble eyes, can someone recommend which ignition-power and +12V wires would be good to tap into and not mess up the module? Just to be clear, by "ignition-power" I mean one that gets juice when the key is turned to the accessory position.
March 28, 201214 yr I always just use a wire harness adapter that plugs into the factory harness. Never had any trouble. But if you have a high draw head unit it's smart to run a dedicated power line straight from the battery, With a fuse of course. And use the switched power thats already in the dash for turning on/off. Just to be clear, the power wires in the dash have nothing to do with the illumination module. The module uses separate wiring which cannot be connected to an aftermarket head unit. There are 4 illumination wires that go to the stock head unit, two of which are in a separate plug a few inches from the main harness plug. Two more which are the same colors in the main harness plug. They are on top of each other in the plug at one end (don't recall exactly which side). Edited March 28, 201214 yr by Fairtax4me
March 28, 201214 yr Agreed - on any of the EJ's you just use the aftermarket radio installation adaptor harness that's like $10 to $15 at any stereo shop. I have a Sony deck with bluetooth in my '91 SS and I've installed countless stereo's using these adators without any problems at all. If the factory radio plug has been cut out - get a reverse harness for it. They sell them to repair damaged radio harnesses and to reinstall factory deck's. Cheap on Amazon or ebay. GD
March 28, 201214 yr Author When I got the car the factory harness had indeed been cut out. I matched up the wiring diagram from the new radio with the FSM diagram and spliced in the harness that came with the new radio (thus destroying the illumination module). I certainly appreciate your harness suggestions, but it seems that would lead to extra work and some expense. I'd have to splice in the reverse harness to the Legacy wiring and then probably end up having to splice together another harness to go from the radio to the reverse harness, as there don't appear to be any pre-made adapters available for my radio. Even if there were, it seems all I'd gain with a new harness or two is some convenience should I ever want to replace the radio. Since it's only two wires causing the problem, I'm really looking for the simplest way to deal with them.
March 28, 201214 yr Yeah with a cut harness just leave the illumination wires unhooked. Track down the ones in the dash and tape them off so they don't short against each other or something metal in the dash. DO NOT connect them.
March 29, 201214 yr I also tried to go your route and figure out the color codes. But never could figure it out and caved in and bought a harness. Best money spent ever!
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