On Tue, 24 Sep 2019 07:58:47 -0500, Terry Coombs
wrote:

** When I got my truck back from our son , lots of things that he just
couldn't be bothered to fix . One thing is the radio power supply . He
did tell me that the radio had "died" , turns out the fuse (in the fuse
block) keeps blowing . I've got the dashboard apart enough to check the
wiring harness and supply wires , can't find any cuts or anything that
looks like damaged insulation ... it works just fine sittin' in the
driveway , but within a few miles driving it blows the fuse . I figured
it was the radio/CD player unit so I got a new one , does the same thing
. I'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 !

Check for any extra connections between the battery and radio. It
could be a loose connection. You'll find your extra amperage going to
warm that connection.
Alt1: Run a separate fuse to a switched hot.
Alt2: earphones and your phone/MP3 player are a cheap and easy pair.

--
There is s no such thing as a hyphenated American who is
a good American.* The only man who is a good American is
the man who is an American and nothing else.* We are a
nation, not a hodge-podge of foreign nationalities.* We
are a people, and not a polyglot boarding house.
--Theodore Roosevelt