i keep blowning the 40 amp electric fan fuse. if i unplug the fan the fuse doesnt blow. this is all while the engine is running with the defrost on. i'm guessing my fan has a short in it? should i run the fan directly to the battery to see if it even works? thanks

 

The point of a fuse is to protect the electrical system from causing potential damage to one or more components. If you want to test for a short use a multimeter and check the resistance between the connections. If you get 0 then you have your confirmation that it is a short without the possibility of starting a fire.

 

With the engine not running, use a long skinny screwdriver, metal rod, or dowel rod to reach through the grille and see if you can move the electric fan blades (they should rotate easily) if, as I suspect, they are frozen in place then the fan motor is locked up and is why the fuse blows. This is a common failure. There are many options on how to fix it (replace the fan), I got a used one from a scrap yard but that's just how I approached it.

 

Replace the fan so you don't over heat your engine when it should be running.

 

All of the above. The fan should spin freely (the one in front of the truck). The bearings start to go, heat up, drag the fan down toward what motor guys call "LRA - or locked rotor amps". The fuse is set below this point, so it will prevent a fire. This is a D2 motor killa, because it is stealthy, people don't realize they are missing that cooling. You also don't have a second fan, like a D1, to compare to.

 

I just went thru the same thing not 2 weeks ago ditto to what Disco Mike and Savannah are saying. I was able to locate a used fan for $55 and it took me all of 30 Minutes to remove and install the unit.

 

Please replace the AUX fan.

The AUX fan is your last defense against overheating.
It is your faithful sentential.

With out that AUX fan, you go to battle with heat without your mighty shield.

 

Couldn't have said it better.

 

thanks Bkreutz, Disco Mike, Savannahn Buzz, Matt3502 and jfall. the fan was locked up and would not spin freely. i'm having it dropped off today at a shop that rebuilds electric motors to see if they can rebuild it. i'd rather try that before i put another LR used unit in.

 

I would be curious to see if you can get it rebuild and the cost, please let us know what you do.