Can you tell me if the 10.9 v looks ok at the red wire?

Well, the battle goes on. One thing I discovered was that the voltage coming into the fuse box (red w/ white tracer) at bottom of fuse was 12.3v, but at the top of fuse was only 11.4v. I cleaned the fuse holder and installed a different 20A fuse. This got me 12.3v top and bottom. Unfortunately, with key on, the radio hot wire still was all messed up. It would read from 2.5 to 11.2v from turning the key on different times. Even at 11.2, the radio would not work. I ran a jumper hot wire from battery to radio and shazam, the radio worked great. That speaker (from a '69 RR) has not made sound since 1975. But I still have my radio wire voltage problem. I wonder if the ignition key switch socket is the problem? The switch was new 2-3 yrs. ago. What do you fellows think, now? It's hard to think real well when you're working on this for hours in 29 degree temp. Thanks for any additional ideas!

Well, the battle goes on. One thing I discovered was that the voltage coming into the fuse box (red w/ white tracer) at bottom of fuse was 12.3v, but at the top of fuse was only 11.4v. I cleaned the fuse holder and installed a different 20A fuse. This got me 12.3v top and bottom. Unfortunately, with key on, the radio hot wire still was all messed up. It would read from 2.5 to 11.2v from turning the key on different times. Even at 11.2, the radio would not work. I ran a jumper hot wire from battery to radio and shazam, the radio worked great. That speaker (from a '69 RR) has not made sound since 1975. But I still have my radio wire voltage problem. I wonder if the ignition key switch socket is the problem? The switch was new 2-3 yrs. ago. What do you fellows think, now? It's hard to think real well when you're working on this for hours in 29 degree temp. Thanks for any additional ideas!