Toyota Repair: dash gauge fuse burns out when put in reverse, light bulb sockets, amp meter

Question
I am puzzled as to why my 1996 T100 blows the fuse to the dash gauges when I place it in reverse (5 speed standard tranny).

My speedometer stopped working before this problem started and I do not know if there is a correlation or not.

I recently had my alternator rebuilt but I still have a problem for there is a constant drain and it is not showing a charge on the amp meter. Any assistance and suggestions will be greatly appreciated.

Answer
As far as the gauge fuse is concerned it may be blowing because of several different reasons, if there is a trailer hitch I would suggest disconnecting the wiring from the rest of the truck to see if the fuse still blows, there are common problems with the trailer wiring converters that may cause this problem. Another reason may be that there is a short circuit in the backup light switch on the transmission, there may be a wrong bulb in one of the tail light bulb sockets.