Help! Radio, door chime fuse keeps blowing.

[goofyfoot53]

I've had this 93 Mustang since about 2014. It had 70k when I bought it and about 105k now. It already had a Kenwood aftermarket stereo installed. It has never blown a fuse in 11 years. A few days ago, the radio didn't start when I started the car. I checked the #11 fuse, but it was good. I checked all the other fuses, and all were good. When I found a different fuse diagram online, I noted that the radio also uses the #8 fuse, which also includes the door and headlight chime, and the side mirror motors. All were out, so I looked again and saw why I didn't notice when I checked all the fuses. The entire plastic portion was missing, leaving only the two metal inserts, which were not connected together, so it got very hot. I pulled them and tried a 15A fuse. It sparked and blew before I got it all the way in. Since I was out of 15A, I tried a 10. It also sparked and blew. Then I realized that since I had to have the door open to access the fuses, the door chime circuit was activated. After buying a pack of 15A fuses, I pushed the door button with one hand and installed the fuse. Everything worked so I thought I was home free. That was yesterday. Today I dropped my wife at work and went to the gym. When I came out, the radio and chimes were out again. Does anyone know what may be happening and how I can trace it? Thank you for any upcoming advice.

 

[91AOD5.0LX]

I am no guru so this advice may not make sense for some reason which others may point out and I apologize in advance if that’s the case but my thought would be to try and isolate the problem by pulling the fuse then disconnect all the components that are powered by that fuse such as the radio and the side mirror switch and whatever else on the circuit that you can unplug…. Then open the door and push and hold the door button and then insert the fuse. Release the door button and see if it blows. If not then plug each component back in one at a time until it blows. That should identify the culprit unless it’s an intermittent problem that is triggered when the circuit heats up or something disturbs a wire. In that case maybe disconnect everything again that you can, then connect just one item and drive for a day or two and if it holds normal then connect a second item and drive the same and after connecting one at a time and using the car maybe that will show which is heating the circuit? Just thinking out loud.
Try isolating each first and see what happens.