Two 30 amp fuses - 12v system

[bw2]

Can anyone help me understand what the two 30m amp fuses protect on the 12v system? The fuse on the right blew. I did not think anything special about blowing the fuse, it had never happened before, so I replaced the fuse and it promptly blew again. Being this was my only spare, I had to wait until today to purchase new fuses. But today, I replced the fuse and all is well, the fuse did not blow. So now I am at a lack of ideas on what to check.

FORGOT TO ADD; 2006 3400RL

Thanks

[Okie Guy]

I have a 2005 Mountaineer 330RKBS which is blowing one of th etwo 30 amp fuses lately. It blew 5 then just stopped. I can't figure it out and the dealer says everything is fine. I hope someone on here can give us some help.