Okay so I have a 91 sdime blazer and the radio harness was completely cut. Found by google the wire color codes but now I lose my channel presets once I turn the key off. The radio I am using is a JVC HD radio I pulled out of my civic when I upgraded. I tied red/yellow together and found the speaker color codes just fine. which wire am I missing for the memory option? thanks.

 

You have to have a constant 12v going to the yellow wire in the stereo harness. The yellow wire is the main power wire for the HU and the constant power is retaining the memory for things like the radio presets and EQ settings. The red wire is the only one that connects to power that is switched on by the key. It works like the remote terminal on an amp to power the HU on.

 

I understand that... On the hu, yellow, power, and red, which I think I remembe as illumination, is twisted together and connected to yellow on the truck, which shows power at key on and acc. The only site I did not connect from the hu was the remote wire. I just recently noticed an orange wire from the truck just dangling there. Does that connect to something? Is that my problem....

 

What he means is that the red and yellow cannot be twisted together. The red is only getting power when the vehicle is on, so when you turn off the truck, the radio doesn't have any voltage to retain any memory. You need to un-twist the yellow wire from the bunch, and wire it to a constant battery voltage. There should be one in the cut harness somewhere in there, if not, you can run your own. Just connect a wire to the + terminal of the battery, add a fuse (preferably as close to the battery as you can) and run that to the yellow wire for the radio. This constant connection to the battery is what keeps the presets, and settings in the memory of the HU.

Also, on a side note. You don't need to connect the illumination to the red wire either. The illumination wire doesn't actually turn on the lights of the radio, it is actually used to dim them for when the headlights are turned on. So if you find that your radio lights are too dim during the daytime, disconnect the illumination wire. If you still want it darker at night, you can wire the illumination wire into the headlight signal so it will dim the lights when you turn on the headlights.

 

Awesome, thank yall.