I have a 2010 Denali and the heated seats do not work. The fans cycle twice and stop, a/c for cooling the seats the work fine. Just had the two control units under seats replaced and it still does it.

The most common cause of this problem is that the drivers seat heater grid is open or burned out. That is based on 25 years as a Ford dealer technician.

Check for power at the fan resistor wire to the resistor, if power. change the resistor block itself. it controls fan speeds. Most resistors are beside the blower fan, below glove box. You may have to remove a panel to get to the fan resistor. check all fuses first! Even under hood fuse box.

He is right about that. The sender unit for the dash gauge is only for the gauge. Another sensor, the coolant temperature sensor, conveys information to the computer about the coolant temperature, and if fans need to be turned on for extra cooling.

This is probably the ac clutch cycling, which is normal. Does it do it when you turn it to max?

You have a broken wire in the seat. The blue wire inside the seat cushion will break or burn in two. If you are handy with tools you can remove the seat, remove the screws from the control switches cut the hog nose ring clips, undo the velcro on the back of the seat bottom and carefully remove the bottom seat cover. You will find that the blue heating element blue wire in burned in two. Cut the bad part out, slide some heat shrink tape over one end. Slide it far enough so that you wont shrink it from the solder gun. Solder the two wires together and keep the joint minimal so that the shrink tape will slide over the solder joint. shrink the tape with a heat gun or hair dryer.Put everything back in reverse order. You will need to go to an older conventional auto parts store and buy a hog nose ring kit with the pliars to replace the upholstery. Go to an upholstery shop and they can tell you where to buy it . It should cost 3 or 4 dollars. this whole seat repair should not cost over $8.00. Also remember check the fuses first and also remember that the seatbelt has to be fastened for the seat heater to work.

overheating can be caused by stuck shut t-stat but u would have heat at-stat stuck open no overheating and no heat. a waterpump that the impeller broke or rotted of can cause your problem but rarly seen does your fan work or any leakage or low coolant can cause air pocket and overheating no heat. let me know and we go foward

Could be a little low on freon as well, causing it to cycle on, off too quick.

test to see if you have any power going through all the connectors for the seat heater, there may be a spot where there is a connector that has gone bad, or potentially it could be the whole element that is bad

EITHER YOU HAVE A CLOSED VENT, OR THE HEATER MOTOR FROM THE FROM IS SHOT.

YOU CAN FIND YOUR FREE ONLINE REPAIR MANUAL AT
http://www.autozone.com/N,316250/initialAction,repairGuide/shopping/repairGuideVehicleSelect3.htm

mabe the blower is geting stuckor if gos of track