radio fuse blows when engine starts

[natedogg]

My 85 has the original radio and it plays fine until I start the truck and the fuse blows immediately. I took the radio out and traced the black ground wire on the harness and cant find anything obvious. Any Ideas? My second question is, what is this wire in the second pic? It was hanging under the dash. Its black with a blue or green stripe. Thanks for any help. I have already fixed several little problems with my truck with help from this great site

[motornut]

the single wire pic looks like it is the fiber optic cable for the ashtray
light from a cluster bulb goes threw this to a small square opening over the ashtray to light it up .
for the other issue,what type of radio?
does it blow with it out?
see any hack wired mods jumpered in the yellow wire?
black plug should have
yellow power
black neg
grey cluster dimmer

[natedogg]

The radio is the stock tape deck. I don't see any hacked up wires. The black plug has the black, yellow and grey wires. I pulled the radio out and plugged up the connections with the wires through the hole as in the pic. It worked fine until I started the truck. The fuse blew. Thanks motornut.

[79Betty]

Jumpered... Made me lol the radio short must be somewhere with the ignition wires i'd say. Sp it still blows with the radio out?

[RastaRobb]

Sorry for being a little slow on the up take but, are you saying the fuse still blew when you had the radio all the way unplugged? If so, it obviously isn't the radio. I would start checking right at the back of the fuse panel.

[motornut]

how it should be,
I used connection 14 to running lights,for night dimming when needed

[natedogg]

The radio works good with just the ignition on, but as soon as I turn key to start with the radio still on the fuse blows. Thanks again guys.

[Greenlee]

Does the fuse still blow when you start the truck with the radio unplugged?

[natedogg]

The fuse blows when I start truck with the radio unplugged.