Ford Recalls 148,663 S650 Mustangs Over Ground Terminals That Can Crack and Cut Power

If you bought a new Mustang in the last three model years, look up your VIN. Ford is recalling 148,663 Mustangs from the 2024, 2025 and 2026 model years because ground connections on the engine compartment wiring harness can fracture, according to the report Ford filed with NHTSA on Aug. 25. NHTSA's campaign number is 26V547000. Ford's is 26C40.

This is the seventh-generation S650 car, and AutoGuide reports the campaign covers both coupes and convertibles. Autoevolution, which went through the filing, says the affected cars were built at Flat Rock, Michigan, between Sept. 7, 2022, and June 9, 2026.

What can go wrong

NHTSA's summary is blunt. A fractured ground can cause a loss of drive power, or knock out the windshield washer system, the headlights, the air conditioning or the engine cooling fan. That is why the cars fail two federal standards: FMVSS 108, which covers lamps, and FMVSS 104, which covers windshield wiping and washing. Losing power in traffic or losing headlights at night both raise the risk of a crash, the report says.

The root cause is a small assembly problem. Per autoevolution's read of the filing, adhesive from the heat-shrink on the harness can creep into the bolt-clearance area of a ground eyelet, and that interference can bend the eyelet as it is installed. A bent eyelet has a shorter fatigue life, and engine bay vibration does the rest.

Ford found it the hard way. In June, its electrical distribution team reported a durability test that ended with two broken ground eyelets and a loss of motive power, autoevolution reports. Ford then decided the condition could exist in cars already built and issued a stop-ship. The company knows of eight warranty claims in the US, four of them within three months of the car going into service, and the filing estimates about 1 percent of the recalled cars have the defect.

Drivers may get a warning first. AutoGuide lists a check engine light, chimes or messages in the instrument cluster as possible signs. If a late-model Mustang starts throwing electrical warnings, take it seriously.

The fix, and the wait

Dealers will replace the engine compartment ground terminals for free with redesigned parts. Autoevolution says the new eyelet pigtails use a different standoff with a stepped neck that removes the interference, and AutoGuide describes them as revised eyelet pigtails. The catch is timing. NHTSA's record says final owner letters will go out once the remedy is available, which is expected in March 2027, and autoevolution puts the deadline for remedy letters at March 31, 2027. Ford is due to send interim letters by Sept. 4.

VINs became searchable on NHTSA.gov on Aug. 28. Owners can also call Ford customer service at 1-866-436-7332 and reference recall 26C40.

What enthusiasts should do now

Check the VIN on every S650 in the family, and on any used one you are thinking about buying. A 2024 Mustang changing hands this fall could easily be one of the 148,663, and the parts are not expected until spring.

If you run aftermarket electronics, such as a tune, auxiliary lighting or a big stereo, this recall is a good reminder that ground paths matter. A shop doing electrical work on a recalled car should know about 26C40 before it starts chasing a gremlin that may come from the factory harness.