Wiring a New Radio into a GM Car (now improved)


Okay, so here's the story...

Earlier this year, I bought a 1985 Oldsmobile Cutlass Ciera from my friend. It's a nice old car; low mileage, previously owned by the proverbial old lady who only drove it on Sundays.

And who, incidentally, enjoyed AM talk radio programs.

The car had a factory AM radio in it. So I bought a new stereo for it, and foolishly neglected to spend 15 bucks on the aftermarket wire harness adapter kit, because I figured, "Well, it's just speaker wire and power, how hard can it be to figure out?"

Yeah, right.

So I remove the dash (no mean feat), finally pull the old radio, and I discover that there are more wires back there. And that 3 of them classify as "power" wires. After nearly frying my new speakers, I grabbed my Web browser and searched madly for any reference to "radio wiring GM harness" and so forth, on all the search engines I could find.

No dice. Only a million other requests for radio wiring tips, from other frustrated do-it-yourselfers.

So, in the interest of saving a few people from ulcers, here's how it works:

(DISCLAIMER: Now, I'm going to assume you're not stupid. I'm even going to go waaaay out on a limb and assume you're not a stereotypical American, hyper-litigous and anxious to blame anyone but yourself for your shortcomings. But you're not the only one reading this page. So, in the interest of my own amusement, here ya go: This is what MY CAR looked like. Unless you're replacing the radio in MY CAR, your wiring may not look or work like my wiring. Follow my advice at your own risk, and always remove the negative battery cable from the battery before mucking about with car wiring. And wash those hands, Laura; look, there's dirt way up under that fingernail. Okay, here's the advice.)

  • The radio wire harness in my '85 Olds Ciera (and other GM cars should be similar) is made up of three 4-wire bundles. I'll call them "top", "middle", and "bottom".

  • The top bundle is for the rear speakers. As my car didn't have rear speakers, it had no top bundle. Speaker wires are easy to figure out, though.

  • The middle bundle is for the front speakers. The colors on my car are as follows:
    • Light green: right speaker +
    • Dark green: right speaker -
    • Pinkish: left speaker +
    • Grayish: left speaker -

  • The bottom bundle is the nasty one. It covers power.
    • Yellow: 12V power when the ignition switch is turned to ON or ACC. This is "main power" for the radio.
    • Black: Ground. Negative-ground, of course. This is an American car, you know.
    • Gray: 12V power when the lights are on, either headlights or just the "running lights". In the factory radio, this was power to the "lighted dial", but my new Aiwa stereo is an "always-lit" type, and this wire doesn't go to anything on it. If you're in the same situation, for Ghawd's sake please cap this wire with a wire-nut before you install the new radio! You could cause a fire if you forget.
    • Hot pink: This wire was referred to as "ANT" on my factory radio's backplate. I have no idea what it's for; it may be a control wire for a "retractable antenna" which I don't have. It doesn't deliver power, at any rate.

  • But that's not all. My new radio required a power wire "that is always on", to retain its settings when the car's off and to run the little blinky red light when the faceplate's removed. It also apparently needs this to run at all; don't ask me why.

    Fortunately, there's a 2-wire bundle, independent of the radio wiring harness, one of which is exactly the always-on power wire I needed. It's the orange wire.

    (That two-wire harness has another wire, but I forget the color. I didn't use it, and have no idea what it's for.)

I hope this does someone some good. Ask me nicely and I might even send you instructions on removing the dash. Just 'cause I'm nice.

Okay, since a few people have asked, I'll give you a hint. The secret is to GENTLY pry the 2 outer air vent doohickeys out of the front of the dash (just the vents on each end) and locate the mounting screws inside the vent holes. These screws hold the ends of the dashboard front panel on (there are others above the ashtray and behind the rubber ring around the steering column, but those are easier to find) and gave me a hell of a time until I found them.

With the front panel finally removed, it's a piece of cake to unscrew and remove the instrument panel bezel (which, incidentally, covers the radio mounting screws too). Voila.

That is all.


this page is my fault. All information is provided without having asked anyone's permission.

Last modified: Thursday, 12-Apr-2001 01:09:55 EDT