So my 2017 F250 after being problem free for the last 5 years and 90k miles has decided that since the warranty is up, now it's time to start having problems.

Just came back from a work trip and fired the truck up for the first time in about a week to get ready to pull my camper this week and it started just fine off remote start, but as soon as I put the key in I was greeted with a new Airbag light on my dash, and then I noticed a slew of other electrical issues, I've gone through and tested everything below:

Radio: Screen Works, Speakers & Sony Amp work & Music Plays, Steering wheel controls work as does the USB ports with car play, however none of the buttons and dials on the center dash work

AirCon/Heat: Nothing works, buttons on the dash don't work, seat heat/cool doesn't work and I can't control the AC through the Sync screen, just stays off

Interior Electric: D/S Front & Rear windows Work, P/S Rear works but no Passenger control. D/S powerfold mirror works, passenger side doesn't but power tow extend/retract works on both sides

Exterior Electric: Front Lights all work fine (HLs and Fogs), Rear Upper Tail Lights/Blinkers work but Lowers don't at all (rapid flash on both Left & Right), Reverse works both sides, after driving it for a bit the TMPS fault came up all sensors offline, and now the keyfob doesn't work at all (Lock, Unlock, RemStart, Horn), but the door pin code still works. Power locks all work incl tailgate.

From what I've seen ppl have been saying a cracked taillight with water in it (don't have any cracks and hasn't rained here in PHX in weeks), Grey connector on frame rail by the spare tire (pulled connector, no water etc - desert life, and reconnected), pulled battery negatives for 40 minutes and reconnected, still having the issues.

Any help would be awesome, can't really afford to drop it at the dealer if I can avoid it. Thank you in advance!!

 

Before doing anything else I would have the battery/batteries load tested.

 

100% this. my 2017 had the factory batteries until 2 months ago. Fine one day, dash messages at weeks later, and a week after that NOTHING. Not even doom lights.

 

I would suspect corrosion of either a ground or a module fault or the connector to a module. And I would also suspect rodents damaging harness. Eliminating those things first. A Forscan or scantool with activation would help.

 

I'd suggest the battery check like mwheue recommended. When mine started having glitches (lost 12 hr clock on screen, easy entry/exit quit working, mirrors not folding/unfolding properly) the batteries were the first thing I checked. I had one that had 55 CCA and the other had 370 CCA. That's on two 750 CCA batteries that were 3 yrs old. Fortunately, they were under warranty so it was a $10 replacement fee. Check the batteries first and then take it from there.

 

Sounds like batteries. We'll see when the OP returns with the diagnosis.

 

Like @harmanrk and @Keith Griffin , my truck gave me some clues that one of the batteries was on its way out. Check Brake System, one mirror not folding when the other did, etc. Went hunting and didn't start the truck for almost 10 days. Dead, dead, dead, Oddly enough, it was the warranty replacement battery that had died. The OEM factory battery was still holding a charge.

In the OP's case, I would also check for rodents chewing through wire sheathing. There are quite a number of reports of that happening and causing all sorts of electrical gremlins.

 

Yup, batteries are the very first thing to check.
And, only sure test is a LOAD TEST, not just a voltage test.
And, for dual batteries, at least one has to be disconnected to get an accurate test, as they are connected together in the electrical system.

 

I had a similar issue with my 17 lariat, center dash dead but screen came on, no controls, no mirror ops, no seat ops, I recall the steering wheel control worked, but no hvac whatsoever, air bag lights and misc warnings popping up.

My issue, was the pigtail plug of the right side tail light blind spot warning sensor. There was a minor amount of moisture, and when I took the sensor off it's internal bracket and i unplugged it, the pins of the connector were green and crusty. I filed with a jewelry file and blew out with air, put some dielectric grease on it and it solved all my problems. Litterally everything worked again perfectly. Good luck

 

I had the same issue... It was a plug by the spare tire on the passenger side frame rail. I replaced both sides of the plug. I tried the grease but mine was to corroded. My windows wouldn't work abs light, hill decent and a lot of other weird things... Haven't had an issue since.. I'm a 2017 Lariat as well. Only gas

 

Alright quick update, I thought I was going to get off easy with replacing the batteries, they were about 3 years old and standing voltage was 11.6, got two new motorcraft batteries topped em off on the charger and threw em in, no dice, same issues persist.

Plugged my EZLynk in and checked codes, there's a few -.-

U0256 - Lost Communication With Front Controls Interface Module 'A'
B124D - Tire Pressure Sensor General Signal Failure
B1182 - Tire Pressure Monitoring System No Sub Type Information
B1D01 - Headlamp Right Low Beam
B1D00 - Headlamp Left Low Beam
B1D02 - Left High Beam Circuit Short
B115E - Camera Module Bus Signal/Message Failure
U2056 - Lost Communication With Front Controls Interface Module 'A'
U0200 - Lost Communication With Door Control Module 'B'
U0142 - Lost Communication With Body Control Module "B"
C1001 - Vision System Camera General Electrical Failure

Time to go crawl under the truck

 

Well I found the issue, looks like a mouse had a feast on the harness, from what I can tell the damage is isolated to this one spot, right off the connector on the driver's side wheel well between the upfitter fuse box and the coolant tank. Would anyone happen to have a part number for this? Hoping I'm lucky and can just cut back the damage and splice a new connector in? *fingers crossed*

Was tucked in there I didn't even see this during the day, flashlight caught the copper strands and some words were said.

 

Wire assemblies are available. But they aren't cheap, may not be in inventory and they may be longer than you want.

 

Trying to find a schematic with part id's so I can figure out what harness / connector it is, any suggestions?

 

You need a wiring diagram with pin out. But I suspect a dead CAN module. Check your network comms. See if slow med and fast are working. See if Vref is accurate. Look under the seats and in the kick wells for water damaged modules if you can.