unlawfl

First off....My mustang has only 20,000 miles and it just fell off factory warranty being a 2007 so dealer option was out. My power driver seat blew a fuse under the hood causing me to have no power to the seat for movement or lumbar. I went to the parts store thinking it was just a blown fuse, no biggie. I put one in (30amp) and pop...blown again WTF and further I wasn't sure if it blew on the seat switch or the lumbar switch. Dammm
I decided to pull the passenger seat fuse under the hood and put it in the driver seat slot and isolate the driver's seat switches to see which one blows it. A 50-50 guess and a $5.00 mistake..... I did this and was able to move the power seat every which way to Tuesday..no problem so I decided to stop. It has to be the lumbar switch or its assembly pulling too much power blowing the fuse as it should. I could just replace the lumbar switch guessing it could be that, but I have no idea if thats it...

Has anyone else had this problem with their lumbar switch blowing the fuse and if so what was your issue and how was it repaired????

157dB

http://iihs.net/fsm/?dir=40&viewfile=Seating.pdf

Looks pretty simple.
Pass side has no lumbar.
I would suspect the lumbar switch
as the lumbar switch is of the polarity reversal type
to spin the lumbar motor in 2 different directions with
one set of windings. Anything broken internally could
cause the positive 12 volts directly to negative and
popping the fuse. But it could be the motor even though
the wiring diagram shows a thermal cut-out inside the motor.
A simple test light would find the fault fast.
But even a 1157 bulb inserted in the fuse location instead of
the $5 fuse is a neat diagnostic trick when fuses are a blowing.
The bulb illuminates when the fuse would normally blow.

MattC74

I know this an old thread. But did you ever fix this? I'm having the exact same issue in my 07.

unlawfl

Yes...It was not the fuse at all but since it keeps blowing the new fuse you will need a new one once you put a "new" lumber or pwr seat switch in. Yes, the pwr seat switch was bad which kept blowing the fuse. I don't know why but maybe an internal short with them. I found a new one on ebay I believe for $20-25 dollars. The switches are a PIA to get out though. You'll see but not impossible. Take your time, my 2 cents. I can't remember if the pwr seat switch next to the lumber switch is on the same circuit/fuse but I believe it was. Check your owner's manual. It's not hard to eliminate which switch is actually bad. It will be one or the other. Whichever one your using at the time when it blows is the bad switch. My was my pwr seat switch and not the lumber switch. The fuses aren't cheap but eliminate which switch is blowing when you use either switch. Good luck