I am looking for help on diagnosing an issue with my power lumbar, located on the driver's seat back. Basically the lumbar motor is a little air pump located in the back of the seat. It inflates a small "air bag" to aid in comfort.
My lumbar function has never worked since owning the truck. I recently took the little motor out of the seat and bench tested it, hooking up 12v directly to the motor, it spins freely and pumps air out of the outlet tube. I reconnected it to the factory
wiring harness and tried the rocker switch..............pushing up it does nothing (no sounds or anything), pushing the rocker switch down (an audible click can be heard from the little silver relay box). Does anyone know how this system works? I
believe pushing the rocker "up" causes the pump motor to pump-up the air bag inside the seat. Pushing the rocker "down" releases the air from the bag. Is this correct? Looking for some insight on this function.

 

Might try this link for tracing down a possible issue with the relay or wiring
https://www.dieseltruckresource.com/...arning-236771/

 

Thanks for the link! Very interesting story about how wires can ground out due to chafing. My next step is to pull the seat side panel off and inspect the switches/wiring harness.

 

I ended up pulling off the side plastic panel that holds the power seat controls and found something interesting. The switch is held together with plastic snaps and one of the plastic snaps was not snapped together all the way, this was the lumbar side of the switch. I carefully pushed the switch together to "re-engage" the snap and tried the lumbar buttons............success! It now works perfectly, the air bag inflates and holds air. When I press down, it deflates the air like its supposed to. Glad it was something simple! I also found out that someone had previously been into the switch area, you can see anti-chafing material and black electrical tape. All of the wiring harness looked good.

 

Good deal. It nice when it turns out to be something simple. And thanks for replying back with the fix. Might help someone else out down the road

 

That is exactly why I try to explain things in detail and provide pictures. Knowledge is power.......just figured I'd pass it along.

 

Late to the thread, but I was going to say check the switches first, they tend to get wet and dirty then lose contact. My seat just quit a couple years back and when I pulled the switch apart it was full of dust and gunk and a couple contacts were corroding...the only one actually working was the lumbar one....