I have started a new post here for this issue, as I did find an original post with the same problem (this saved my sanity), but it had a subject for the 2017 and since I have a 2019, I just wanted to ensure people knew this issue still exists.

I picked up my 2019 F350 in the middle of December and from day one everyday was a new adventure. At first I thought perhaps I was doing something wrong with the first few issues, but it soon became apparent something else was going on. First issue was related to Sync 3 not recognizing voice commands, GPS not being found and the screen going black and randomly rebooting or just locking up. For this problem, the dealer re-flashed the software and so far knock on wood, Sync is working fine again and hopefully the APIM unit is OK.

Now to the fun stuff, and hopefully this will help others here. This is a list of all the issues I was having:
- Pre-Collision Assist Not Available Sensor Blocked message. Sensor was perfectly clean
- Pre-Collision Assist System could go off with the full warning on the dash as the red line on the windshield and pre-charge the brakes. This happened a few times times, roads perfectly clear, daylight hours, not a soul in sight and radar unit perfectly clean.
- Rear Parking Aid is disabled
- Rear Parking Aid would go off like I hit something backing up.
- Driver's side power running board would not always deploy
- Interior lights would not always turn off
- With the heat on, I would get cold air on occasion blowing out of the drivers floor vent, while passenger side, dash and windshield vents were all hot air.
- Blinker lights began blinking really fast when signal was activated and I would touch the brake pedal.
- Blinkers began blinking fast all the time, like a bulb was out. They looked like a strobe light going off.
- Brake lights would flash at random
- Reverse lights would go on and off or stay on for extended periods. This really pissed people off at night following me. It took me about two weeks before I was finally able to get the person behind me to stop and tell me why they were flashing me or following me with their high beams. It was cause I was blinding them with my reverse lights
- When backing up, I would get a picture of the truck on the Sync screen with a red dot in the middle and an alarm but no codes or other messages.
- Remote Start would not always work, tried both the key and the FordPass app.
- Blind Spot Failure (random)
- Cross Traffic Alert Failure (this eventually became permanent)

After A LOT of research, I found an old thread here on this site, where johndrush had very similar problems to what I was experiencing, his truck is a 2017. 2017 Superduty - Major Electronic Issues
Pictures from the original thread:
Pictures Of Wiring Harness
Pictures Of Corrosion In Plug
Pictures Of Connection Under Truck

Thank goodness for this thread, as johndrush not only posted his symptoms, which was like I had wrote it myself, but also posted some pics with the culprit in post 25 on the above thread. I took this into my dealer and showed them the thread and pictures. Later that day when I went to pick it up, they told me that the pictures look like they came from my truck - WOW.

There is a plug that is part of the main wiring harness, this plug is located under the truck at the rear on the right side of the spare tire. This plug was full of water, it is not waterproof, and the mechanic said it had no dielectric grease in the plug, which it is supposed to have. The amount of corrosion after just a couple weeks was insane in that plug. It was cleaned up, filled with grease and put back together as a temporary fix. Since this wiring harness is tied into just about everything, it is crazy the chaos it caused.

A whole new wiring harness has been ordered, and this is a pretty big job. They will need to drop the def tank, fuel tank and a bunch of other stuff, to replace this as it runs the entire length of the truck. Post 68 in the original thread, shows the plug itself, connected under the truck. Post 117 on this page, shows just how extensive this wiring harness is.

Anyhoo, the new wiring harness has arrived and I am scheduled to get it all fixed up next week. I will keep everyone posted as to how this goes and hopefully will have some pics as well. Fingers crossed this does fix this entire mess.

 

Pic of the harness plug? I would like to check mine

 

 

I have modified my original post as I figured out how to directly link to the posts with the pictures. ;-)
Click This Link To The Original Post
Pictures from original thread:
Pictures Of Wiring Harness
Pictures Of Corrosion In Plug
Pictures Of Connection Under Truck

 

 

Yes, it was on my 2019 that is only a month old. I seen that someone on this forum had it on their 2017.

 

Just want to add, that I live in Ontario Canada, and we are in the midst of winter with all that road salt and brine, along with the roads being really wet a lot, so this definitely helped accelerate this problem.

 

Yes we all know Quality is Job 1 at Ford LOL!

 

 

 

 

I have had my truck less than a month now and have taken all the plugs apart under the truck and put dielectric grease in them. I even coated the outside where the wires go into the connector...it will probably collect dirt there but the grease should keep out the moisture. Like Redrockerstl55 I am in the STL area with rain/snow and the addition of salt and brine on the roads all winter long.

 

^^^^^^^^^^^^^ Smart Man!!!!!

 

 

Q: using dielectric grease, do you fill the connector or do you simply coat the 'walls' inside the connector? if the grease is dielectric, does it negatively affect the electrical conductivity between the gendered pins? any insight is appreciated, thanks.