The fuses blowing are most likley a short some where in the wiring system though you could check out the brake switch and multi-switch.
The trans should have two switches on the driver's side. The first one should be your "back-up light" switch the second "neutral safety" swiltch.
Make sure the connector is plugged in. With key in "run poistion" ( in park and brake on) take off connector take solid wire (house wire) put one end on each side of connector, go see if back up light are on. If not you have broken wire or burned out bulbs.
If they work take out switch (deep socket size ? on 5 spds it 22mm) spray ball (move ball in and out by pushing on it) and connectors (female and male) with contact cleaner with lubricant(if you have trans fluid under ball you mite have to use wd-40 to fush out) . Then spray connectors with contact that dries. Attach connector to switch press down on ball (have some one look at lights) to see if they go on.
If lights go on put switch back in, If lights do not work you will need new switch.
I took my "back-up light" switch out three time, the first two time a sprayed down with wd-40 and used solid wire to scratch female and male pins the thrid time I used contact cleaner and it stll working.