My 2004 yukon's heated seats will not stay on. The button lights up for a few seconds and then turns off. This happens on both the drivers and passenger side.

Yes that's normal. it should go off as soon as you open the door though. if it doesn't then they will go off when timer expires (normally about 90 seconds) after you leave the car.

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.

May have a bad door switch or bad relay.... Get the seat where you want it and disconnect the harness under the seat till you can get it repaired....

Check the fuses, the owners manual should be able to help you there.

When this was happening on my Envoy it ended up being the seat heaters control module that was going out. About $600 a seat on mine. Just wish my repair center found that out before they replaced the seat heaters twice.

The controller could be bad but I would probe the related wiring first. From your symptoms it sounds like something can not handle the electrical load. You turn the F/R seat heater on but then you turn on the F/L and the whole system fails. It does sound like the source of the problem will be under the drivers seat. Testing needs to be performed to confirm and identify the source. Both seats share the same fuse and ground. This circuit may have a damaged wire or connector somewhere. Inspect and test as much as you can. Also look underneath the seats for anything. Customers are not aware that personal belongings and trash get pushed underneath the seats and will damage wiring. Also excessively moving the seat forward and back will weaken the harness over time. Please write back and let me know what you need. If it is more diagnostic information or suggestions just let me know. Good Luck

check your personal settings. my brothers did the same until he reset the personal settings

See GM TSB 05-08-143-001, If you have Adjustable pedals, especially if they don't work with the memeory buttons, but function with thier own buttons. Its the Brake Pedal Position Sensor is shorted and mesing up the seat module which controls the heaters too. My 05 Suburban had the same issue

check the rail system on the seat. sometimes it pulls the wire out and it doesn't get good enough connection

I have a 2006 yukon and have had to replace the actuator in the rear heat/ac twice.  It moves a valve that closes the cold/hot ducts.  It is a cheap defective part/design.