I have a hummer h2, driver side seat heater does not stay on but passenger side will. i have replaced heat pads already, but have been told its probably a relay. where are they located

Not a fuse issue , more then likely a burnt heating element in the seat , happens all the time .
Heated Seat Components
The heated seat system consists of the following components:
• Driver and passenger heated seat switches
• Driver and passenger seat back heater elements
• Driver and passenger seat cushion heater elements
• Driver and passenger seat back temperature sensors
• Driver seat module
• Driver door module
• Passenger door module

The control module have a Battery voltage supply , the module supply's voltage to the seat heating elements .
The heated seat switches are momentary contact switches and are inputs to the driver and passenger door modules. Battery voltage is supplied to the switch assembly from the door module, and when a heated seat switch is pressed and released a brief switch signal voltage is supplied to the door module. Whenever the door module receives an active heated seat switch input, the next heated seat operating mode is determined by whatever the current mode may be. The seat heater elements are controlled by the driver seat module using inputs from the door modules through Class 2 serial data circuit messages. The driver seat module controls the voltage supply and the ground circuits to the seat heater elements. When a heated seat function is commanded active, the seat module will switch battery voltage to the heater element supply circuits, and ground is provided through low side drive control circuits. During heated seat operation both the seat back and cushion heater elements are supplied battery voltage. The seat module grounds the appropriate control circuits for back only or back and cushion heating modes, and opens or closes the active control circuits as necessary in order to maintain the desired seat temperature. The seat module relies on inputs from thermistors located in the driver and passenger seat backs to control heated seat temperatures. The thermistors are 2 wire sensors supplied with a 5-volt referenced signal circuit and a low reference circuit from the seat module. Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the seat back temperatures rise. The seat modules allow heated seat operation only while the engine is running which is determined by a Class 2 serial data circuit message from the powertrain control module.

Your best bet , take it to a qualified repair shop.

I believe you have separate temp controls for driver & passenger side check the manual if you have one

They are not vac on the h2. there is 2 for temp control, one for recirc and one for blend. check the hummer forum as there is a great read for it there. the driver side actuator is really ez as it's under the glovebox, 20 min fix. the rest take removing the whole dash but it's not that tough.

try sitting on a few phone books lol no sorry but if there not working it would have to be a fuse or breaker or relay check them first before taking it to a shop.

Yes their should be one on the front driver side and one on the passenger side by the fire wall......Hope this helps.

check drain tube

check your fuse box for blown fuses and check the wiring going into the door and see if it got pinched wires

Check the wires under the seat sometimes they frae when moving the seat back and forth.

Also they will auto turn off it is getting to hot or a wire inside the seat is contacting another wire so check where you can for bad contact.

Hope this helps

The body control module in this vehicle sees a short in the seat heater system. These vehiucles are typical of the heater wiring shorting out. When you try to use the bad heater the computer shuts off all the heaters.

You will need to install a new seat heater pad.

THIS HAPEN TO MY H2 I REMPLECE THE UNIT IF TAKING THE BATTERY DID'T RESTAR THIS UNIT THEN YOU HAVE TO REMPLACED UNIT