Fuse keeps blowing

I started my truck today to go out with a few friends and when i put the key and turned it over i lost my lighting for my gauges and i no longer have parking lights or tail lights, The fuse was blown changed the fuse with a new one, it worked for a little while and blew again, any ideas?


Marsal

what year and type of vehical. all I know is sierra

1994 Gmc Sierra Ec 4x4

sry was a little tired when i made the post forgot all that additional information.


Marsal

for startrers check the wire harness in the rear of the truck behind the rear bumper. there is a plug-in that connects the R&L rear lighting. this would be the plug where you add a trailer lighting pig-tail.
If this corodes and you loose ground, this is going to cause a high amp draw and bolw a fuse. Another plug-in is right next to the fuel tank and leads to the tank sensor.
Also the rear tail lights themselves have circuit boards within.
Remove the tail lights and see if you notice anything burned looking.
If you have a pig-tail for trailer already, try removing it and trying it without it pluged in. these pigtails cause plug-rot as well.
just a few thoughts to get a start.