Electric seat motor switch...no move back

Power Seats System Description and Operation
Power Seat System Operation
There are 2 options of power seat systems available in full size trucks. The 6 way driver and passenger power seats, and 8 way driver and passenger power seats with driver memory. For the driver memory seat operation refer to Memory Seats Description and Operation . Power seats without memory are completely controlled through the power seat switch. Battery voltage is supplied to the power seat switch through the power seat circuit breaker. While the seat adjuster switches are in an inactive state the switch contacts are closed to the power seat switch ground circuit. When a power seat switch is pressed to an active state the switch contact is closed to the battery voltage supply circuit. Each seat adjuster motor is controlled by the power seat switch through 2 motor control circuits. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.


( I'm not good at wiring an running an ohm meter.) well then you need to take it to a qualified repair shop.

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? 1:44
https://www.youtube.com/watch?v=EDh-0rs5Fjo
Oct 26, 2010 - Uploaded by automdvideos
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Is it possible that switch has been installed upside down?

You don't mention what year your Yukon is ? This could very well be a control Module problem .
I'll post how the power memory seat's work or are suppose to work !

Memory Seats Description and Operation

Battery voltage is supplied to the memory seat module through a 25 A circuit breaker. The memory seat module supplies the seat adjuster switch assembly with a battery positive reference voltage. While the seat adjuster switches are in an inactive state the switch contacts are closed to the adjuster switch common circuit. When a seat adjuster switch is pressed to an active state the switch contact is closed to the reference voltage circuit. Battery voltage on a switch signal circuit indicates to the memory seat module the switch status is active. Each seat adjuster motor is controlled by the memory seat module through 2 motor control circuits. While the seat adjuster motors are in an inactive state the motor control circuits are closed to ground circuit contacts within the memory seat module. The memory seat module operates the seat adjuster motors by switching one of a motors control circuits to battery voltage. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.


Memory Set/Recall Operation
The seat adjuster motors are equipped with internal position sensors. The adjuster motor position sensors are monitored by the memory seat module and are used to determine the seat position when storing or recalling memory settings. The driver seat adjuster motors use potentiometer type position sensors. The position sensors are supplied with a 5 V reference and ground circuits from the memory seat module. The position sensor signal circuits return to an analog input within the memory seat module. During adjuster motor operation the position sensor provides a voltage change proportional to the change in revolution of the adjuster motor shaft. The memory seat module monitors the voltage from the position sensor signal circuits to determine the adjuster motor positions when storing or recalling memory seat position settings.
The memory recall switch assembly on the driver door provides inputs to the driver door lock/window switch. Battery voltage is supplied to the memory recall switch assembly from the driver door lock/window switch. When a RCL 1, RCL 2, or EXIT switch is pressed, the switch contacts close the appropriate switch signal circuit to the battery voltage supply circuit within the memory recall switch assembly. When the driver door lock/window switch receives active switch signals from the memory recall switch assembly, the appropriate commands are sent to the memory seat module using the GMLAN Serial Data circuit. The Body Control Module software version determines the personalization features available.
Memory seat recall operation is allowed only with the transmission selector lever in the PARK position while the ignition is on. The transmission selector lever position data is provided to the memory seat module by a message through the GMLAN Serial Data circuit.

There are somethings listed you are not familiar with , like GMLAN Serial Data circuit ,maybe Body Control Module software etc... GMLAN is a communincation network that the computers on the vehicle uses to share information , transmit commons etc... you can google it to read about it .

There are DTC'S - diagnostic trouble codes that can set in the module in control . Do you know what DTC'S are .

DTC Descriptors
DTC B1825 01: Driver Seat Recline Position Sensor Circuit Short to Battery
DTC B1825 06: Driver Seat Recline Position Sensor Circuit Short to Ground or Open
DTC B1825 5A: Driver Seat Recline Position Sensor Circuit Plausibility Failure
DTC B1850 01: Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Battery
DTC B1850 06: Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Ground or Open
DTC B1850 5A: Driver Seat Lumbar Horizontal Position Sensor Circuit Plausibility Failure
DTC B1860 01: Driver Seat Lumbar Vertical Position Sensor Circuit Short to Battery
DTC B1860 06: Driver Seat Lumbar Vertical Position Sensor Circuit Short to Ground or Open
DTC B1860 5A: Driver Seat Lumbar Vertical Position Sensor Circuit Plausibility Failure
DTC B2355 01: Driver Seat Front Vertical Position Sensor Circuit Short to Battery
DTC B2355 06: Driver Seat Front Vertical Position Sensor Circuit Short to Ground or Open
DTC B2355 5A: Driver Seat Front Vertical Position Sensor Circuit Plausibility Failure
DTC B2365 01: Driver Seat Rear Vertical Position Sensor Circuit Short to Battery
DTC B2365 06: Driver Seat Rear Vertical Position Sensor Circuit Short to Ground or Open
DTC B2365 5A: Driver Seat Rear Vertical Position Sensor Circuit Plausibility Failure
DTC B2375 01: Driver Seat Assembly Horizontal Position Sensor Circuit Short to Battery
DTC B2375 06: Driver Seat Assembly Horizontal Position Sensor Circuit Short to Ground or Open
DTC B2375 5A: Driver Seat Assembly Horizontal Position Sensor Circuit Plausibility Failure

5) Memory Seat Module is under the front of the driver seat , you could look under an see if all the connectors are fully seated.

The best diagnostic step would be to hook up the factory scan tool an see what the computer is seeing as far as inputs from the switch an outputs it's sending . I wouldn't suggest you take the seat apart an try testing electrical inputs etc.... unless you very familiar with automotive electrical systems an circuits .

I just went through and determined it was the switch. My wife had accidentally moved the seat almost all of the way forward - and the reverse did not work at all - she was very cramped. After going thru fuses and seeing that none were blown I looked for loose wiring under the seat and found none. I was about to pull the seat when I stopped and decide to pull the side cover first. Item 5 in the photo below. Once that was off access to the switch was easy - item 3. The box actually contains a set of 3 switch housings each with 2 switches on it - total of 6 for each direction. I unplugged the large connector to this switch. Then I cut some wire off of a roll of wire i had in the garage and stripped both ends. I put one wire into the power contact (red) and the other into ground (black) and then took the other end of both wires and connected them across the other contacts in the connector. Pretty quickly I could determine which pair of contacts controlled which motor. I got the right combination that allowed me to operate the seat-reverse motor and get the seat back into the right position... problem solved. I still need to find a replacement switch box at a junk yard but no hurry now that the seat is back to a comfortable position.

I had the same problem on my 2003 Toyota Camry. The threaded drive screws are what spin underneath the seat and cause the seat to move back and forth (same way a garage door opens or closes). When the seat gets all the way in the forward position, the threading on the drive screws ends, which causes the bolts connected to the seat to jam and get stuck. It should sound like the motor is trying to turn but it won't, it just clicks. Un-jam the bolts and rotate them one rotation from the all the way forward position to ensure your seat is reinstalled straight.

Electric or manual??? If electric one of the motors has gone out. If the kids were playing with it they may have held the button down causing the motor to spin while the seat was all the way foward and it will just burn the motor up after so long. Also the switch could be bad. Unfortunatley being that its power there is no way to manually move the seat back without the motor turning or removing the seat and spinning the motor sprocket by hand...

This is not necessary...as many have stated...use a hammer with switch in reverse position. Hammer the seat back...it will catch...

Before you start beating up thing's , test the electrical circuits. Do you know anything about automotive electrical systems ? How to use a volt meter an a wiring diagram to test for B+ power to the switch an testing the ground .
Does your envoy have memory seats ? Your vehicle has four or more electric motors to control back an foward , up an down etc.. the odds of more then one motor being bad at one time are highly unlikely .
Look under the seat any trash under there keeping it from moving ?
If you have memory seats there is a control module involved in making the seats work . If it has memory seats it could have DTC'S - diagnostic trouble codes .
DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820
The seat adjuster switches are inputs to the driver and passenger seat modules. The seat modules supply the adjuster switch assemblies with a battery positive switch supply circuit and monitor the switch signal circuits. In an inactive state the switch signal circuits are floating and when a switch is pressed the signal circuit is closed to the switch power circuit within the adjuster switch assembly. When battery voltage is present on the switch signal circuit the seat module determines the switch status to be active.
DIY Blazer GMC Jimmy Power Seat Control Diagnostics and Repair Electric...

Motor on the seat may have gone out, contacts in switch got dirty or worn, or assembly reached limit and stuck. Try sitting in it pushing back hard and adjust. If not youll need to replace switch,b take seat apart to fix or replace.