[Joe Wicked]

Loose battery connections can also cause fuses to blow. With an intermittent connection on the battery you have a changing load on the electrical system as a whole. This can cause surges of power, or drains of power. You tend to see more drains when the neg is loose and more surges when the pos is loose, but you can get both issues with either. A sudden surge of power will cause a sudden increase in amps going through a fuse causing it to blow. Certain types of battery connectors will cause this as well. I worked on one Cobra that had a battery connector that did not secure very well to the cable. Changing out the connector fixed the issue.