My F-150 Gen 12 Lost Power While Towing Uphill in Hot Weather

If you’ve ever had your Ford F-150 Gen 12 lose power while towing uphill in hot weather, you know how nerve-wracking it can be. I found myself in this exact situation, and after some investigation, I discovered that the issue is more common than I initially thought. Thankfully, there’s a well-documented cause and a clear solution, backed by a Technical Service Bulletin (TSB) from Ford. Here’s what happened, how I temporarily fixed it, and the steps I’m taking to ensure it doesn’t happen again.

The Problem: Sudden Power Loss While Towing

There we was, towing my trailer uphill on a particularly hot day, when suddenly, my F-150 lost all power. The engine just cut out, and I was left coasting to a stop on the shoulder. The dash lit up with warning lights, and I knew I had a serious problem on my hands. After a bit of troubleshooting, I realized the root of the issue was the 20A microfuse responsible for the fuel pump circuit.

What Causes the Power Loss?

This fuse is prone to overheating, especially when the truck is under heavy load in hot conditions. When the fuse overheats, the fuel pump shuts down, leading to an immediate and complete loss of power. It’s a problem that can strike without warning, making it especially dangerous if you’re in the middle of a climb or navigating heavy traffic.

My Temporary Fix: Replacing the 20A Microfuse

Once I figured out that the microfuse was the culprit, I replaced it with a new 20A microfuse. Here’s what I did:

• Popped the hood and located the fuse box.
• Found the 20A microfuse for the fuel pump circuit in position 27.
• Swapped out the blown fuse with a new one.

This got me back on the road, but I knew it was only a temporary fix. The underlying issue wasn’t resolved, meaning the fuse could blow again under similar conditions.

The Permanent Solution: Ford’s TSB 15-0137

To prevent this from happening again, I turned to Ford’s Technical Service Bulletin (TSB 15-0137), which offers a more permanent fix. This TSB addresses the overheating issue by recommending the relocation of the fuel pump fuse from its original position to a new JCASE fuse slot.

Summary of TSB 15-0137 Instructions

Here’s a quick summary of what the TSB 15-0137 involves:

• Identify Fuse 27: Start by locating fuse 27 in the fuse box, which is currently a 20A microfuse.
• Wiring Modifications: The TSB provides detailed instructions on how to modify the wiring to accommodate the new JCASE fuse. This includes extending or rerouting some wires to reach the new location.
• Install the JCASE Fuse: Once the wiring is set up, install the JCASE fuse in the newly designated slot for fuse 27. The JCASE fuse is larger and can handle higher currents, which helps prevent the overheating issue.
• Test the System: After completing the modification, test the vehicle under similar conditions—towing uphill in hot weather—to ensure that the problem is resolved.

Links and References

For anyone dealing with this issue, I recommend checking out these resources:

• Ford TSB 15-0137 Document (PDF)
• NHTSA Recall & TSB Database
• Ford F-150 Owner’s Manual

Having my F-150 Gen 12 lose power while towing was a stressful experience, but knowing that there’s a clear fix makes all the difference. Replacing the 20A microfuse on the emergency lane of the interstate was a quick way to get back on the road, but following the steps outlined in TSB 15-0137 is essential for a long-term solution. If you haven’t dealt with this issue yet, I’d recommend addressing it sooner rather than later to avoid any surprises on the road. Safe travels!