I have a 2005 FX4 Crew cab with heated mirrors. When I push the button it flashes on and then immeditately goes off.. Is this normal without ice on them or is there a problem?

 

Just checked my 2006 in the heated garage. At 54*, turned them on, and they stayed on. I only have the heated mirrors, the rear window is a power slider.

with the heated mirror status light flashing, the relay and fuse for the heated mirrors appears to be good ( power taken from after the output of the heated mirror relay & fuse for the mirrors ), so I would take this to mean short in the heating element in the mirror, or the mirror element is not being seen. Hope that is the source, as the other candidate is the HVAC panel

did the heated mirrors work last year ?

 

curious---does the circuit have a timer built in like the rear defroster? after it's on for a certain amount of time, it automatically turns off. maybe the timer bad?

 

The mirrors and rear window are on the same relay.

The time function, best I can tell, is in the instrument cluster.

Button on the EATC or EMTC is pressed and the input is sent to the instrument cluster. The instrument cluster grounds the coil on the heated rear window relay, which powers fuse #8. This is the fuse to the heated mirrors.
The same circuit that powers the mirrors is what illuminates the heated mirror / rear window status LED on the HVAC cluster.
The best I can tell, is I am working from memory:
1. The external item buttons on the HVAC panel are momentary switches ( at least I know the heated seats are )
2. When the time runs out, the instrument cluster would remove ground from the coil on the heated rear window relay, and it shuts the circuit off.

Guess the easy way to check would be to pull the heated rear window relay, and jumper the normally open contacts.


He would want to get some water on the mirrors to turn to ice, don't know if you can tell by touch if the mirrors are working.

 

They never worked. I got the truck with 22,000 on it. I will check it out.