[KevinH1990]

Here are a few things to check if you haven't done so already:

Experiment with the fader (front/back) controls. I know you don't have rear speakers, but the doors are a blend of the front and rear sound. Adjusting the control could provide a higher-level signal to the doors. Also turn up the bass to see whether that makes a difference.

Were the door speakers working before you swapped the head unit? If the speakers were working, it could be an issue with the new CDR220. To confirm that, you could reinstall the CDR210 and determine whether the door speakers are working. If you remove the head unit, look for damaged wires behind it. There is a lot of wiring packed into that area and some of it could have been damaged if it got caught between the head unit and the dashboard structure.

If you suspect a problem with the amplifier, I have a 4X40 Haes amplifier I can send you for the cost of shipping.

If you suspect a problem with the wiring, you can use a multimeter to check continuity from the amplifier to the door speakers. Unfortunately, that will require you to remove the door cards to access the wiring in the door. That will also allow you to determine whether the door speakers are defective.

I have to go to work in a few minutes, but I will search for the wiring information I found when I upgraded my door speakers when I return home tonight.