I would guess that it more then likely started as a bad connection at one of the fuses and just spread from there, but you will need to check your interior fan motor (was it working on all 4 speeds?).

I would just buy a new relay and suitable fuse/circuit breaker and bypass the damaged fuse box and old relay mounting socket.

 

Yes was working on all speeds so I ruled out fan resistor but will check fan for normal operation as suggested. Think I will do a clean out of the system while I am there.

Yes I was thinking the relay was in the circuit for a good reason. So will buy relay and fuse holders and bypass fuse box.

Much thanks.

 

Fuse box bypassed

Finished the fuse box bypass.

Used the original 'power in' wire (thick white wire) from relay base to new relay and made up two wires to run the relay activation from relay base to new relay. The inline fuses are connected to the same relay pin. The 2 x blue fan wires then come off the inline fuses.

Seems to be working so far.

Used:

60amp 5 pin relay (only need to use 4 of the pins though)
2 x 30 amp mini fuse holders

A new relay from Nissan is $60.

 

Just a quick question, as I have a similar problem with my fuse box:,

I noticed that the fuse cover says "Blower motor 1" and "Blower Motor 2".

The cable for Blower motor 2 has been cut. Just wondering what that one does and if I need it.
My fan seems to still be working ok