Thread: 04+ Radio Bench Test Hookup Help

Well, I'm attempting to bench test an 04+ base radio and so far have been unsuccessful. Here's the pinout I have, and I'm not sure what is correct.

Purple writing is for other gm stereos that use the same plug and aren't used on this radio.

Highlighted parts I have wired to battery. 15Amp fuse on B1 and 5Amp on B4 just to be safe.

CD player makes the "turn on noise" and the lights on every other bulb turns on. Haven't hooked up a speaker yet so that's next. There's absolutely no backlight or display even dim.

When I took the radio apart, I noticed all three bulbs were burnt out so I replaced them and tested the bulbs both out and after installation.

Pretty sure this radio is toast, but I figured I'd post this before I get a new one a screw it up too.

And yes, I have to bench test because I only own a 2002 so....

I think you're right. I wired up a speaker and started playing around with it some and found something interesting. The display actually comes on with the time and lights up when you push the tune button, but doesn't stay lit for a few seconds then it goes off. Only buttons that I can tell are working are the hour and minute button can change the time and the tune can illuminate the display, but that's it. Theft light isn't lit. Just strange... Anyone seen this before? I'll try googling and see what I can find.

Well, I think I might have found the problem, but not sure if there's a solution. Turns out that this is normal behavior for the radio with no key in the ignition. Now normally there's an ignition wire that tells the radio that it's ok to turn on, but unfortunately, at least with the stock wiring, there is no ignition wire so I'm assuming the signal is through class 2 data?

On the metra harness, there's a pin B2 that isn't present on the grand prix that's supposed to be ignition voltage. On the radio, there is a pin for B2. I'm wondering if it wold work to just insert that wire and connect it to power.

I think I'm going to give that a shot since there were a dozen of these radios in the junkyard, and I can easily grab another one if this shorts it out and exchange for free.

Nope, no change. I'm suspicious that there's nothing wrong with the unit other than it doesn't have class2 data telling it it's on. I'll try with another junkyard unit and if I get the same result, I'll know.

I don't think it's theft locked. Or, at least it isn't turned on enough to say it is. From all the videos I've seen, the theft lock led will illuminate, and the radio will display "locked". None of the videos I saw had anything like I did. I also noticed that all the videos on replacing the backlights didn't bench test them but tested them directly in their car, so I'm thinking that's a reason.

I think at this point, I'll try removing the security chip, and if that doesn't do anything, I'll see if someone here wants to give it a shot for me in their 04+ gp. (I'd pay shipping both ways of course). Idk, maybe this chip removal does something

Originally Posted by WarStryker13

If you want the legitimate wiring diagrams, look no further:

04+ Factory Service Manuals, Owner's Manuals, and assorted helpful info.

Thanks man! Looks like my info is correct. I'm leaning toward class2 data not present is the only issue, but I'll try a few more things.

Yeah. I found on another forum that it looks like these newer radios use class2 via the bcm to tell the radio to turn on instead of ignition voltage. I think I'll just have someone test one for me in the car, but at least I know all the lights and display works!