Retrofitting a Class 2 Data Radio Into a 93 Pontiac Firebird

[1993TransAm]

This whole idea started because I used to have a Delco cassette player in my car. The head unit was nice and it controlled a CD changer, but after a while I wanted to be able to spontaneously listen to a CD inside the car. I also didn't want to give up my ability to listen to cassettes, because I'm old school like that. A good friend of mine installed a double-DIN Pioneer radio into his 1999 Camaro, so I figured fitment wouldn't be too much of an issue. He suggested that I install one of the double-DIN CD/cassette radios from a Grand Am in my car. So, after a lot of research, soldering, and getting the Grand Am radio to fit in my car, I did. Just one problem...the Grand Am radio was not capable of controlling a CD changer. I installed a Sony 10-disc unit with a wired remote, but I just didn't like it. So, out with the Sony and the Grand Am head unit. I scored a U1Q unit from a 2001 Bonneville for very cheap and set off to get the thing to work in my car.







Here's how the Bonneville radio retrofit started. Due to the "unsuitability" of the factory flatwire connector as a surface to solder stranded copper wire to, I soldered the wires directly to the terminals in the radio cavity. I was kind of nervous about this as I had never soldered quite like this before, but I figured if it doesn't work, I could just desolder the wires. Not to mention the radio only cost $35 from a junkyard. I used a Scosche wiring harness for my Trans Am to act as a "frankenstein" harness. There were 8 additional wires that were not accounted for in the harness (Class 2 Data, illumination ground, amplifier gain control, switched battery voltage, and the left, right, common, and drain wires from the remote CD changer). I used a pair of rear 4-wire speaker connectors I found in a 1995 Bonneville SSEi to facilitate these wiring connections.

Are these pictures too big?

[phoenix_flame220]

How did you simulate the Class II data bus connection? The deck gets a data signal to turn on, a standard switched accessory power will not work.

[1993TransAm]

I did exactly that...I transplanted a Class 2 Data bus into my car, Dash Integration Module and all...more pictures to come soon.

[1993TransAm]

Here are some pictures of the radio installed in my car. I also retrofitted an N-body (Grand Am/Alero) Monsoon amplifier into my car.

[The_Maniac]

Out of curiosity, did you get the wheel controls to work?

[1993TransAm]

Out of curiosity, did you get the wheel controls to work?

Yes, I did, but it was quite a "PITA." Unlike the Grand Am (and the Firebird) where the radio looks for certain voltage levels on the steering wheel control circuit that correspond to commands, the Bonneville radios (as I am sure you are aware) respond to Class 2 signals over the data bus. The Dash Integration Module provides both the reference (supply) voltage to the steering wheel controls and converts the appropriate return voltage to a Class 2 signal. I hid the DIM in the spare tire well underneath the passenger side hatch panel, so I had to run wires for supply voltage all the way to the steering wheel controls, and a return line from behind the radio (where the factory SWC wire is) back to the DIM. Additionally, I had to run switched voltage and Class 2 Data lines to and from the DIM, respectively (this is how I created my own "data bus"). The radio (obviously) and the remote CD changer also sit on this bus. I was able to keep all the wires hidden, running them underneath the molded carpet and behind trim panels. (For example, that black flex tubing that runs along the center console in one of the pictures is now gone.) I'll get some more pictures up soon. Thanks for your interest in this project.