electrical problem

[chucks70]

Always something new. Went to leave work last night and no electric in the truck. PO installed an inline fuse where the fuseable link would be off the battery, it blew. Is 20 amp, replaced it. Truck started, on the way home it blew again. I was about 6 miles from home, replaced it again. Drove a little while, a headlight blew then the fuse blew again. Happened to have a heavy guage piece of wire which I jumped the fuse line with, started home again. Now about 2 miles from home the other headlight blew. Got home verrry carefully as I only had parking lights now. Truck still running I pulled the jumper wire off and truck still ran for about 5 min. Don't think it was running on the battery because I removed the jumper wire and when I revved the engine the lights got brighter. After a couple of minutes though the truck quit again. Put the jumper wire back on and started no problem. I have had no problems electrically with the truck for about a 8 months or so

Should the inline fuse be stronger? Could it be a bad voltage regulator(only about 8 months old)? Bad alternator?

Any help would be appreciated.