After upgrading to the LT mirrors - I sold my orig Lariat mirrors to a guy over on another Ford Truck site and he had an XLT....with power but no heat or turn signals. He plugged them in and said everything worked - so in his case the the harness was already set up for the heat and signals as he already had the power. And the heated mirrors work from the rear defrost button.

 

Thanks for the info guys.

 

so he already had the rear defrost so they worked?

If you don't, then I don't see how they would work without getting the defrost/heated mirror switch for the dash (which may require another wiring harness too?). My FX4 has the heated mirrors and you have to press the switch in the dash to turn them on. I don't have the rear defrost window.

TXF150, do you have a rear defrost window?

 

No, I don't. Im really not worried about the heated mirrors, but I really want the signals in the mirrors to work. Mirrors will be arriving tomorroe. I will keep you guys posted on wheather or not the signals work.

 

Good point Steve - he must have already had the RWDef.....I have noticed on my Lariat that both the rear sensor and power sliding rear window harnesses are there - seems as if Ford is using one harness for most of the F-150's....at least the Lariats anyways.