cat 416c 4 wheel drive prob

Hi, I have a cat 416c. When the 4 wheel drive is engaged it works momentarily then it blows the fuse for the 4 wheel drive and the clutches, makes a clunk sound then the 4 wheel drive disengages. I'm assuming the sound is from the solenoid when it loses power and the front axle disengages. My manuals for this machine recently burned in a fire (along with my shop, office and all my tools) so i could use a little help. I will look for a bad wire but, could a faulty solenoid be shorting out and blowing the fuse and how do I test to see if it is faulty. I'm guessing it is located underneath on the transfer case but, an exact location would be useful. Also is there anything else that could be causing this problem. All the clutches work fine until the 4 wheel drive is engaged.

Thanks for any help.