Does anyone know why the rear Auxiliary A/C blower on a 2004 Sport Trac keeps blowing fuses and how to fix it?
Thanks,
Wrb36usa (wrb36us@aol.com)

 

The electrical draw exceeds the fuse rating....

Either a bad blower motor or a ground/short on the circuit.... Philip

 

Thanks, aquanaut20,
The blower motor will run after I put a larger fuse in the system, then it blows that fuse also, so it must be a short in a wire.
I guess I will have to pay the big bucks for the dealer to find the short.

 

Using a larger fuse than the circuit is designed for is a good way to melt wiring.

If you put the correct fuse in, then turn the rear blower to a slow speed, does the fuse still blow?

-Rod

 

Thanks shorod,
You are correct. When I insert the right fuse and run the blower on low, it works just find.
But, when I turn the blower to a higher speed it blows the fuse.
Can you tell what my next move should be?

 

To Shorod,
You are right.
I put the fuse it calls for and put the Auxiliary rear blower on low and it works OK.
But, when I change to a higher speed, it blows the fuse.
What do I do now and thanks.

 

It sounds like the problem is the blower motor itself then. If it were a direct short to ground, the fuse would blow anyway. Instead, it sounds like you may have an issue with the blower that is causing it to draw more current than the circuit is rated for. It could be a bearing that is worn and loading the motor, it may be an issue with the motor windings.

From what I can tell of the wiring diagram, it appears for low speed the blower motor is just along for the ride, probably relying on airflow from the cabin blower motor. For Medium speed the ground for the rear blower is routed through a resistor which effectively limits circuit current, keeping the fuse from blowing. When on High speed, the rear blower has a straight path to ground through the rear blower control switch, no current limiting. There is a thermal fuse in the rear blower motor resistor block, but that thermal fuse is in circuit regardless of speed setting.

-Rod

 

OK, Rod
I will look at getting another blower motor. Do you happen to know where it is located in the vehicle and how to go about changing it?
Thanks
Bill

 

The rear blower motor is located in the center console, underneath the storage compartment. You need to remove the console to replace it. It doesn't appear to be a trivial task. If you'd like a copy of the service manual removal and reinstallation procedure, send me a Private Message with the request and an e-mail address for you and I'll send you the PDF procedure.

-Rod

 

Rod,
I do not know how to send a private message on this web site. Please email me at: wrb36us@aol.co with the PDF file you mentioned in your post to me about the below Quote.
Thanks,
Bill
The rear blower motor is located in the center console, underneath the storage compartment. You need to remove the console to replace it. It doesn't appear to be a trivial task. If you'd like a copy of the service manual removal and reinstallation procedure, send me a Private Message with the request and an e-mail address for you and I'll send you the PDF procedure.

-Rod

 

The file should be in your inbox from my Gmail account.

-Rod

 

I count myself lucky to have Rod take the time to answer my request for help, on Ford Truck Enthusiasts. He is a very knowledgable person and seems to have access to a very extensive auto repair library.
Thanks again, Rod

 

Sure ROD gets all the credit....

This should have provided a start point/direction... Philip