Hey guys
So I have an odd situation. I have an 04 f150 4 door XLT. My power locks still work. When I go to roll down any of my windows in my truck my mirror defroster light turns on. Then when I let up on the button it turns off. But when I turn on my mirror defrosters the window switches lights turn off. I'm figuring I have a short but thought I would see if anyone out there has more info for me. Thanks

 

Can you roll the passenger window down using the button on that door? If so the first thing I would try is to replace the window control unit in the drivers side door. Don't really know what to say about the whole "mirror defroster" thing though

 

Check the rubber boot between the door and the cab on the drivers side for broken or shorting out wires. Known bad spot for wire issues with the door locks. Also, you can take the drivers switch apart and clean the contacts, that helps alot as well. Plenty of threads on this site with individuals that have had to clean the connections or fix the wiring in the door boot.

 

Thanks guys I pulled that boot back and found about a 10 gauge wire broke. So I spliced it back together with a longer piece of wire and now it works great.