New electric fan blowing fuses.....Help?

[n737nc]

I just installed a new electric fan. I had to hard wire it straight to the battery.

Here is how I have it wired,

From the battery, I have a 12 gauge wire going into the cab to a 30amp togle switch. Then from the togle switch, it goes back into the engine compartment to an in line 20 amp fuse. From there it goes to a 40amp relay, then to the fan. all with 12 gauge wire.

My problem is that it keeps blowing the 20amp fuse. The fan will run great while it is idleing. But, if I take it for a drive, come back 20 min later the fuse is blown.

I went up to the parts store to get a couple of extra fuses, and they tell me that a 20amp fuse is not enough for an electric fan. Is this correct? They rcomended at least a 30amp. I stepped it up to a 25amp.

I am kinda scared to go any bigger on the fuse. I don't want to burn up anything.


Anyone have any idea's? Everything is new(fan,togle,relay, etc...).


Nick