omalley1537

I have a 2007 1500 CC/SB 4x4 VMAX LTZ with Bose, NAV, Rear Entertainment, etc. I bought it a couple weeks ago with about 40k on it (one owner). Yesterday, I tried to use the driver's seat controls and none worked (lumbar or base/back controls or memory controls). They acted like they unhooked from a battery source (i.e. no movement whatsoever). I cycled the key, even started the engine, nothing. Tried the passenger seat and it worked fine. Seat heaters worked fine. After one key cycle I got a short (less than one second) movement out of one of the controls, then nothing again. During this entire time I was parked, other than a brief movement forward (I had to move up on the ferry I was on).

After a while, full control was restored and I didn't have any further issues-all functions were normal. I drove for approximately an hour and a half and while driving lost function again. Both times the seat heaters had been on so I thought that maybe I was overheating something (circuit breaker/thermal protection etc) so I turned off the seat heater. Drove for awhile but no luck even after heater cooled off. Got home and stopped at the mailbox. Put truck in park and got that one second or less movement again, then nothing. Pulled into the driveway and shut the truck off, then got out. Now have full use again.

As a result of all this I have ruled out the motors as when they work they function without issue. Seat heaters also work fine. Passenger seat has worked fine throughout. I assume that it would not be a fuse since it has worked intermittantly.

Any ideas anyone could give would be greatly appreciated as this is out of warranty and I only want to go to a dealer as a last resort.

Lloyd-TX

iTrader: (1)

Here's a TSB to start with . . .

Good luck!

omalley1537

Cool, thanks for the info! I will check that out as soon as I can and post back (hopefully if it works it will help others with a similar issue in the future).

Lloyd-TX

iTrader: (1)

Yep - I'd like to know if this is the fix. I own an auto repair shop and it would be helpful if we ever run into the same issue.

Lloyd-TX

iTrader: (1)

A couple more pdf's just in case . . .

omalley1537

Thanks for the additional info/diagrams. I pulled the cover, both the lumbar and power adjustment switch plugs were seated firmly. I have not had a chance to check the truck again as far as running the seat heaters and checking the seat function, but I am guessing it is something else due to the connectors being seated fully already. I am going to check the seat wiring harness and module under the seat when I get more time, I am wondering if there is a wire shorting or something. I am also going to check any circuit breakers/relays if there are any. Thanks again for the info and I will keep you updated of what I find.

Lloyd-TX

iTrader: (1)

Crap - oh well, it was worth a shot.

Did you disconnect and re-seat the connectors anyway?

omalley1537

I didn't R&R, but I did push to make sure they were seated (they were). However, I think I may have stumbled upon the issue. I have now driven the truck for two days (I don't use it on work days) and have yet (knock on wood) to have a repeat of the issue. I started looking and there is a huge wiring harness plug on the floor by the rear of the seat. When I was having the issue that area was full of stuff (returning from the fam's holiday gathering). I think all the stuff in that area may have pushed on that harness enough to break connection intermittantly. If that was the case, the plug is in a bad spot in my opinion-seems like it should be centered under the seat where nothing would reach it.

omalley1537

Wanted to give an update and a new request for thoughts from the more experienced folks. My issue has continued. I have found that (a) the power pedal adjustment also ceases to function when the seat is acting up and (b) other than occasionally fixing itself while driving, most of the time the only thing that works is to turn off the truck and open the door (so as to lose the retained accessory power). This had me looking for a circuit breaker (figuring that it was resetting upon losing power, allowing proper function again) but I haven't been able to find one that would involve the related circuits. This has me stumped. I feel like if I were to take it to a dealer they would try to sell me a new seat base and/or go into "change parts until it's fixed" mode.