I have the scematics to just about every mopar radio, however, I don't have a copy machine .
If you want to send the radio in, we will be glad to service it. If you want to attempt it yourself,
I will provide you with the Sams # . It should be in AR 61 . Their are a couple minor differences and model numbers for the '69 B body AM ,and they are slightly different inside. If you provide me the 7 digit part number on the tag , I could tell you for sure which manual you need.
These Sams AR manuals are pretty easy to find on e-bay .

Greg