1979 ford f-250 camper special
 

How in the heck do i change the fan in the fan box?? What would be the easiest way? The fan was going out for about 3 months makin a grinding sound then all of a sudden one day it made a loud pop!! and now nothing works. I checked the fuse and its good. I need to put the new fan in anyway before winter gets here
also the truck does have air conditioning. I also have another problem. when i try to start my truck it goes to crank but instead acts like the battery is dead. And slowly starts to crank and the only way i can get it to shut off is to pull the posative battery cable off. The key wont even turn it off. i have changed the starter and battery and solenoid twice. also it does work for a couple weeks then ill go to start it and the battery will be totaly dead?? and if its not it will just slowly slowly crank over and over again. Please help. Been trying to get this running since i got out of the Army. and im going crazy!!:-X19

U.S Army Infantry 11B thanks in advance
400 motor
3/4 ton full time all wheel drive with no locking hubs. just when i need 4 wheel i put it in lock in the cab