On Tuesday, September 24, 2019 at 10:02:52 AM UTC-4, rbowman wrote:
On 09/24/2019 06:56 AM, Terry Coombs wrote:
'm really puzzled by this , from the way the fuse was spattered it's got
to be a dead short to ground . I think it very unlikely that the new
radio/CD unit is bad - the old one did work when I replaced the fuse ,
for a few miles same as the new unit . This is an '86 GMC pickup , I'm
hoping someone here might be aware of a known problem area that I might
check ... I gotta have tunes !

What else is on that fuse? Does it still blow if a radio isn't connected?

http://forum.73-87chevytrucks.com/sm...?topic=11766.0

'radio' isn't jumping out at me but your eyes might be better.

Sounds like an intermittent short in the supply wire. Try driving with the radio off and see if the fuse still blows. If so, you can try to follow the wire back to find it, or else maybe run a new wire with online fuse from somewhere. You can sell the radio on eBay.