With all the lights and the fan turned off, does it still blow the fuse? If so, then you probably have a direct short to ground. You'll need to troubleshoot to find where that short is located.
If it doesn't blow the fuse with everything turned off, then turn things on (then back off), one at a time. The item that blows the fuse is where to focus your troubleshooting. It could be wiring to that item or it could be the time itself. You'll need to do some "investigating" to determine which it is.
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