I have an '04 FX4 with the turnsignals in the mirrors and was wondering if I could swap those out with heated mirrors instead?

 

huh? If you already have the turn signal mirrors (signal bar is along bottom black part of mirror), then they should also be heated mirrors too. Don't you have a button on your dash that has a little mirror icon on it? The button should be to the right of the A/C recirculation button.

Do you have a self-dimming rear view mirror?

In 2004, the standard FX4 side view mirrors are just power adjustable. If you have the "deluxe mirror package" option, you get power side mirrors with turn signals and heated function, and a self-dimming rear view mirror.

Therefore, I never heard of having turn signal mirrors without the heated function.

 

I think the heates mirrors are an added option. Most likely you would have to add a switch for the heated mirrors. I know on my lariat, they have some timer that will turn them off after awhile. something you might have to add..

 

I do have the auto dimming rear view but I only thought the lariat had the heated mirrors with the turn signals.

 

My 06 XLT has heated mirrors with turn signals.

 

It's all a part of the "deluxe mirror package" option like I said above. That option is available on XLT and up models.

so, again, you should have that little button on your dash. Haven't you noticed it before? Unless you have a solid rear window with defrost, then you use that same button to turn on your rear defrost too.

Turn your truck on, and turn on that button. after a minute or so, feel the mirror glass with your hand and it should start to feel warm.

 

Best thing is to look at your owners manual.