Pro Power Ground Fault when its wet out

[FordRetiree]

Hi everyone. Tried searching on this topic before posting, sorry if I just didnt find my answer - I WAS getting non-stop ground fault error every drive cycle during the recent huge snow melt period. MY25, had it 6 months, totally no issue til just now. It's in the cab/front area, i can keep the rear outlets powered without tripping, but trying to reset the cab/front immediately retrips. I scheduled dealership visit (tomorrow), and then of course, it stopped couple days ago.
Will dealership be able to find anything - what is others experience? I saw some posts similar to this from a few years ago, but nothing recent. Evidently there was some TSB in 24, and then seems pretty quiet. I have the fordpass record that shows the issue existed repeatedly - i think i have 40+ alerts.

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[Firn]

Iirc the regular F150s were having similar issues and it was traced to a connector in or near the rear wheel well.

I dont remember the details, I just remember reading about it some time ago.

Google response.

he F-150 Pro Power Ground Fault Issue
Yes, there is a well-documented issue with the Ford F-150's Pro Power Onboard system triggering ground fault errors due to moisture.
The Cause
The problem typically stems from the electrical connectors located underneath the truck bed, near the rear bumper where the Pro Power inverter box is mounted.
Water Intrusion: These wiring harnesses and connectors are exposed to the elements. During heavy rain, snow, or even trips through a car wash, water can seep into connections that weren't perfectly sealed from the factory.
System Sensitivity: The Pro Power system is highly sensitive to safety hazards. When moisture bridges the gap in these unprotected connectors, the system detects a leak in current, throws a "Ground Fault" warning on the SYNC screen, and shuts down the circuit to prevent damage or electrocution.
Common Solutions
Owners and dealerships have handled this issue in a few different ways:
The DIY Weatherproofing Fix: Many owners have successfully resolved the issue by locating the exposed connectors under the rear of the truck, unplugging them, blowing them dry with compressed air, and packing them with dielectric grease. They then wrap the connections tightly in electrical tape to create a watertight seal.
Dealership Harness Replacement: In cases where the moisture has caused corrosion or a dead short from a wire harness rubbing against the bed mount, dealerships have had to replace the affected wire harnesses entirely under warranty.
Checking Frame Grounds: Occasionally, the issue is caused by frame grounds that have started to corrode. The fix involves removing the grounds, cleaning the contact points with a wire wheel, and sealing them with silicone.
(Note: There was also an unrelated software bug on earlier models where simply pressing the "Test" button on the SYNC screen triggered a ground fault error, but Ford addressed that specific glitch via an Over-The-Air software update.)

 

[FordRetiree]

ok thanks for this info. I guess i'll still go to dealership tomorrow, maybe they know where to shoot some water to check the system. or at least the usual checks and precautions to do.

 

[chl]

So many vulnerable wires and connectors under the truck and elsewhere. When the weather gets better (warmer and dryer) and before the mosquitoes emerge, I plan on crawling under there and taping up whatever looks like it could use it.

 

[rtk11226]

Does anyone have a diagram or pictures of these connectors? I was having this exact problem about a year ago… dozens of errors and then nothing for days or weeks and then another random burst of errors. I always assumed it was a loose connection but every time I was about to head to the dealership the problem would clear. Haven’t had it reoccur in months.
thx

 

[chl]

Does anyone have a diagram or pictures of these connectors? I was having this exact problem about a year ago… dozens of errors and then nothing for days or weeks and then another random burst of errors. I always assumed it was a loose connection but every time I was about to head to the dealership the problem would clear. Haven’t had it reoccur in months.
thx

Might be this one in this thread:


https://www.f150lightningforum.com/forum/threads/unplugged-wiring-harness.34872/#post-646432

 

[chl]

Here was another connector problem - corrosion:

https://www.f150lightningforum.com/...-u019b-fixed-post-45.33226/page-3#post-628878

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