It doesn’t take much to bring a modern muscle car to its knees. In the Mustang’s case, all it takes is a ground connection that won’t stay put.
Ford is calling back 148,663 seventh-generation Mustang coupes and convertibles from the 2024 to 2026 model years over engine-bay wiring that can quietly fail. The ground eyelet terminals bolted into the engine compartment can suffer fatigue fractures, and once one lets go, the consequences ripple outward depending on which connection breaks.
One broken eyelet, a cascade of failures
Lose the wrong ground and the car can lose motive power entirely — the headline risk, and the reason regulators care. But that’s only the start. A fractured eyelet can also knock out one or both headlights, the windshield washer pump, the air conditioning, or the engine cooling fan. Because headlights and washers are covered by federal standards, an affected car technically stops complying with the law.
The root cause is almost absurdly small. Heat-shrink adhesive used on the wiring harness can, thanks to production variation, seep into the bolt-clearance area of the ground eyelet. That intrusion bends the eyelet during assembly, and once it’s bent, ordinary engine vibration steadily chips away at its fatigue life until it snaps. Drivers usually get some warning first — a check-engine light, a warning message, or a chime — before anything actually quits.
Ford stumbled onto the problem during durability testing rather than out on public roads. Two eyelets on a 2027 Mustang test car broke and cost the vehicle its drive power, prompting the automaker’s safety office to dig into current production. The finding was serious enough that Ford slapped a stop-ship on 2026 Mustangs the same day. By early August it had logged eight related warranty claims, half of them within the first three months of ownership, and says it knows of no crashes or injuries. It also estimates only about 1 percent of the recalled cars actually carry the defect.
The fix is free and straightforward: dealers will swap all four engine-compartment ground terminals for a redesigned part. Ford describes the new piece as using a “stepped-neck terminal geometry” that eliminates the clamp-up interference and the out-of-plane bending stress that doomed the originals.
And then the second recall landed
Barely a beat later, Ford issued a separate campaign covering 10,001 vehicles from the 2026 model year — and this one spreads the pain across the lineup. It sweeps in Broncos, Bronco Sports, Explorers, Rangers, and a smaller batch of 237 Mustangs, tied together by their engines. The 2.3-liter EcoBoost sits at the center of it, alongside Bronco Sports running the 1.5-liter unit.
The failure here is inside the block itself. Piston domes can crack where the nickel-resistant ring insert meets the aluminum, a crater crack capable of causing engine failure and power loss. Ford blames a manufacturing slip at the piston supplier: a loose lock nut on a machining tool let it periodically strike the Ni-Ring insert and damage the bond, while an ultrasonic tester that should have caught the cracks may have missed them after a replacement sensor’s parameters weren’t updated.
Accounts of how many engines have already failed differ. One tally points to 38 failures at the plant and 13 suspected in the field, while another puts it at 22 plant failures and two out among customers as of August 12. Either way, no crashes or injuries have been reported. Dealers will inspect every affected engine and replace the entire long block, free of charge, on any car found with cracked pistons.
Owner notifications for the wiring recall were due to go out this week, with the piston remedy mailings expected in late December. Anyone unsure whether their car is caught up in either campaign can check the NHTSA recalls site by VIN.
