I am making my own wiring harness for my audiophile sub, and the wiring diagram says to connect the power wire (12 ga) to the #38 25 amp fuse. How do I go about tapping into the fuse box for this power source?

Thanks,

Jesse

 

I don't know about your truck but mine has no #38 fuse in either the power distributuion box or the inside panel and no 25 amp fuse used any place.
I would suggest you use an inline fuse holder and crimp an eye connector on it's end for connection to the plus battery cable terminal right at the battery.
Then complete your wiring to the equipment in a manner that will be solid for no shorts and with the correct size fuse in the holder so there is proper protection should a power failure occurr with the lead or the equipment.

 

The nicest product I've seen for tapping into an existing fuse is called Add-A-Circuit. Simple, safe, reliable, relatively inexpensive and available at most auto parts stores. Better yet, when you want to remove it, no damage has been done to your Fuse Box.