I need a Hi/Lo converter...
If it is something else, please enlighten me![/b]
The problem is that the bose headunit doesn't amplify the signal at all, so it is a line (low) level output. When you swap that out you are putting in an amplified high level output in its place. That will not go over well with the bose amps. I don't know how the amp/amps are hooked up to the headunit in the 01, but it is probably a harness instead of RCAs. When I had mine apart the other day, I could not find the power wire for the amps on the harness, so I believe that they are powered through a relay somewhere, which is why I couldn't see it with my meter, so hooking up the amp wire should give you power. If you pull the harness off the bose amp and take a multimeter set to voltage, touch the black lead to ground and the red to each pin on the harness and you should see 12 volts somewhere.
You have a few options on how to go from here.
Run the high level wires from the headunit directly to each speaker (you would have to check the impedance of the bose speakers to see if this is possible)
or you could do the first option while swapping in aftermarket speakers.
Wire in a line level converter between the headunit and the bose amps
Wire the preamp outputs on your headunit to the bose amps
Swap in aftermarket amps
If it were me I would probably go for aftermarket speakers amplified by the headunit's internal amplifier. The cheapest option is using the line level converter, but you might find that there is a lot more wiring and identifying wires involved. Let me know if you want more info on any of the options.