I don't know of any internal fuses - i have not opened the case yet.
You can try
www.rush2112.net (there some other suggestions here)
I was able to get one on ebay for about $50 US, including shipping.
Progress: -- -- >30%
Ford F-250 SD: VIA 1.5GHz, 1G, 32G Patriot SSD, XPSP3, RR(04-2010), DX4, iGuidance 2009,
Directed DMHD1000 HDRadio w/ mjs Cable