Where is the radiator cooling fan fuse?

93 dodge ram installed electric radiator fan, now truck dies?

• I have a 93 dodge ram that I recently replaced the water pump and the original pump the fan was seized and rusted into the pump and I was unable to even get the fan apart. So I decided to get a 16" Electric Radiator Cooling Fan 12V 2750cfm. I ran the fan to a wire tap to the inside fuse panel and tapped into the radio fuse. I started the truck up everything worked fine, the fan spun, everything was working. So this morning I go back out to start it up and its dead. No crank, nothing. I checked the battery with a multimeter and it red about 12.45V. Despite the voltage being normal in my opinion I notice the interior light was not on like it should be if the door is opened. So I jumped the truck and it started right up first try. I then found that the fan must have blown the 10amp fuses from the fuse tap for the radio so I I swapped in 20amp fuses into the tap and they held strong. I got about 100 yards down the road and the truck completely shut off and was electrically dead. I checked the 20amp fuses they were fine. I got another jump and it started right back up. Does this mean my battery cannot handle the amp draw from this fan? Could it be that I cannot use a fuse tap off of the radio? What would cause the truck to act dead but still hold a 12.45V charge?

• Answer:

  First off, swapping a 20 amp fuse for a 10 amp factory fuse is a quick way to roast some wiring. Put the 10 back in. Second, you have apparently put your tap for the new fan after the fuse in the radio circuit - Move it so you tap power off before the fuse, then put an in line fuse holder in the fan wiring so the two circuits are separate. Is there some form of temperature sensor in the fan circuit ?? If there is a temp sensor, then the fan should be wired to a circuit that is not switched with the key, so the fan can run after the truck is turned off, until the engine is cooled enough to pop the temp sensor.