CR-V Mk3 sat nav/cd radio lifeless

I`ve just searched 70 pages of threads looking for a solution to my problem with no joy!! This doesn`t bode well.
I have a 2007 Mk3 CR-V EX I-CTDI and recently the 40amp battery fuse blew. After renewing the fuse everything worked except the sat nav/radio.I checked the radio fuse, number 34 which was OK and there is power reaching fuse 34 when the ignition is on. So I removed the whole sat nav/radio and found two live wires amongst the nine plugs that fit in the back of the unit which suggested to me that the fault was with the sat nav/radio unit. I then spent £250 on a non returnable replacement unit and of course this did not solve the problem!!!! So, even though there is two live wires feeding the back of the unit, they are small thin wires and I`m thinking that may be one of the chunkier wires is the main feed. During my search for ideas I found a mention of a navigation fuse but no details.
Has anybody heard of a navigation fuse or know of another fuse that might effect the sat nav/radio unit?
Also, is there a workshop manual available for this vehicle that would have wiring diagrams as I would like to know which wire is the main power supply to the unit so that I could trace it back to source.
Finally, does anybody want a Mk3 sat nav/ radio?? Thanks for reading.