I have been thinking a lot about the 7.5A backup fuse lately. Under what circumstances is it normal for the backup fuse to blow? It's blown on me twice now. The first time was when my battery went dead. Not sure if it blew when I jumped the car, but I knew for sure that it was blown because the radio didn't turn on. I also blew the fuse when installing a CD player a few days after first getting the car. At first I thought the CD player was broken, but then I realized after checking every fuse in the car that it was the Backup fuse. This makes me wonder what relationship the backup and the radio have with each other?

Thanks!

 

Check for a short/exposed wire/damage in the Wht/Blu wire at the rear of the radio.

 

I pulled the radio but didn't see anything on that wire. There was a little exposed wire on the battery (yellow) and the ground (black) wires. I put some electrical tape on them and reinstalled it.

 

The Yellow and Black wires have nothing to do with the Back Up fuse. If the fuse continues to blow, as seems likely, then one at a time unplug components (clock, radio, ECU) on the Back Up fuse circuit in an attempt to identify an unplugged component that prevents the fuse from blowing.