[Grumpy old man]

I was bench testing a few radios yesterday , I have one with the same issue and I was using a spare full size battery . I found pulling on the tuning R knob increased the volume slightly so I'm going to try some contact cleaner . another I set up worked great and the first station that tuned in was a local 70's rock station ! I sat and listened to it for a while when my girl walked in she looked at what I was doing and asked "Does it only play old rock songs ? "

There are GM am radio repair manuals on ebay