AC Fan short ?????
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AC Fan short ?????
I have a 2002 Expedition with the 5.4 liter Triton and all of the sudden as the wife is driving down the road the front A.C. blower blows the 40 amp fuse under the hood. Was wondering if anyone has a wiring schematic that might help me find the problem. It has to be a short either in the wiring, switch, or fan itself. Anyone with help to this problem please speak up and help me solve this if you can! Thanks in Advance!
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Joined: Jul 2003
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From: Lawton, Oklahoma
Is this an Eddie Bauer with EATC or manual AC? Is the short dead or intermittent? If it is a dead short you can start by pulling the blower relay, then the EATC blower speed controller, then the blower until you eliminate the short. You can alternatively start with the blower.
With manual AC the order is relay, blower motor, resistor, and blower switch.
And naturally all wiring in between the components.
Its not a common problem so I dont have any first guess to offer. Ive never seen it happen here yet.
The relay is in the blower flasher relay box, which I believe you will find under the lower dash trim panel area to the right of the steering wheel toward the center of the dash.
With manual AC the order is relay, blower motor, resistor, and blower switch.
And naturally all wiring in between the components.
Its not a common problem so I dont have any first guess to offer. Ive never seen it happen here yet.
The relay is in the blower flasher relay box, which I believe you will find under the lower dash trim panel area to the right of the steering wheel toward the center of the dash.
Last edited by HomerWinzlow; Sep 10, 2004 at 06:07 PM.
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It's not an Eddie Bauer .....it's an XLT. When you say start with the relay are you talking about the relay in the fuse box ? I had just about eliminated that being the problem cause it is also the relay for back-up lights and they are working. I thought if they worked then the relay must be good ? Does that sound right to you ? I was planning on unplugging the blower first and then sticking a fuse in it. It appears to be a dead short so if that keeps it from blowing the fuse then it has to be in the blower (I'm thinking) ! If it blows the fuse again then it has to be in the switch or the the resistor chip on the blower. In that case I would replace both since a switch is only 12 bucks and a resistor is only about 14 bucks. Does this sound like good thinking to you ? THanks!
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thanks Homerwinzlow..........I was able to get it back working again this afternoon. I did it by trial and error and worked it out ok it seems. I unplugged the wiring harness from the fan blower and then the harness from the resistor chip. Then I went back and put a good 40 amp fuse in the fuse box under the hood. I cranked the truck up and turned the AC to MAX AC and then I turned the fan switch to every speed and then back to the off position. I went back out and checked the fuse and it was still good! So I figured the short had to be in the resistor or the blower motor. I plugged the resistor chip back in and tried to whole process over again. Luckily I didn't blow a fuse again so I pretty much figured it had to be in the blower motor. Did you realize those 40 amp fuses are about 5 bucks a piece ??? Well I called around and found a replacement blower motor for 36 bucks at O'Reilly's Auto Parts and put it in and I got air again! So apparently I had a short in the fan motor. Thanks for all the help!
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From: Lawton, Oklahoma
Glad to hear you had success... 
Yep those maxi fuses are pretty heafty in price. Then you have the 175AMP MEGA fuses that are even more expensive. BUT better to have blown fuse than melted wiring and other goods.
Yep those maxi fuses are pretty heafty in price. Then you have the 175AMP MEGA fuses that are even more expensive. BUT better to have blown fuse than melted wiring and other goods.
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