Toyota Repair: Tacoma blowing fuses sporadically, electrical converter, run music

Question
In June '03 I acquired a '96 Tacoma 4 cyl. auto, x-tra cab. I put about 12K
miles on it annually, it's at 130K, maintained religiously, gets good mpg by
not going over 65. I love this truck. I've had no major problems with it, BUT...
at the end of Oct. it first blew the fuse that controls the brake lights and
getting out of park. Replacing the fuse corrected the problem until end of
Mar. when it happened again. It also blew the turn signal fuse. Fuses
replaced, everything okay - until this morning. I replaced the 15 fuse twice
and it blew repeatedly. The 10 fuse is also blown. My mechanic whom I trust
says it would be easier to solve the problem if it wasn't so erratic. I pull a little
trailer (4x6), but the wiring on that has been checked and declared fine.
I don't have any fancy gizmos or lights. I have one light on the camper top
and I use an inverter to charge my phone or run music from my laptop, but
the fuses have blown with and without this usage or trailer.
PLEASE - any suggestions will be welcome.

Answer
A common problem is that the electrical converter for the trailer wiring develops an intermittent short and causes the fuse problem, I would suggest disconnecting the the trailer wiring completely from the rest of the electrical system and then see if the fuse blowing goes away, if it does you have found the problem.