it usually took 1-2 miles before mine were warm

but I could only take maybe 5 minutes before my backside got too hot

 

I think it has something to do with the heat when your not sitting on it radiates up into the cab, rather than heat the leather....then when you sit down it traps the heat better in the leather...

 

It gets cold in Canada where I drive. I was driving from Saskatoon to Edmonton AB last week and the temp was -40 degrees C for a portion of the drive.

Anybody know anything about the timing circuit or bypassing the relay?

 

I would assume the heaters in the f-150 are the same as a f-350. If so there is no timer.
There are two thermal switches in the seat portion. When the seat is warm enough the switch opens and breaks the circuit. Once cooled enough the circuit closes and the element heats again.

 

Nope, they're different.

 

They are different as I've ridden in the Lariat F-350 2005 model year. Those switches are located on the seats and they do stay on, except for the thermal cutout.

The F-150 has a pushbutton located on the dash. It is located right above the ashtray and one for each seat. There are three settings that you get when pushing, they cycle through. High, Low, Off. There are red lights right above the switch indicating the state of the heater. There is a 10 minute timer located somewhere in that circuit that will turn off the heater in the seat. You can repress the button and heat will return. There may be a thermal cutout in the F-150 seats as well, not sure.

It's the 10 minute timer portion of the circuit that I am looking to modify or bypass. Even if you know where I could get a schematic of this circuit would be helpful. 2004 - 2008 F-150 factory heated seats.

 

This is for a 2005 F150 Lariat 5.4L. I just picked a year between 2004 and 2008. This is all I could find. Nothing on the illumination circuit or the switch. I hope this is some help

 

Timer must be built into the modules themselves...Good luck.

 

hum....i wonder what voltage runs to the actual heating element.....bypass module altogether????? put it on a switch with power on only relay......