2024-2026 Ford Mustang Recall: Wiring Harness Ground Connection Failure/FMVSS 104, 108

The failure that produced this recall happened to a car Ford was deliberately trying to break. On June 4, 2026, a 2027 model year Mustang on a durability rig snapped two ground eyelets in its engine compartment harness and lost motive power mid-test. Ford issued a stop-ship on 2026 Mustangs the same day.

NHTSA campaign 26V547, filed August 25, 2026, covers 148,663 Mustangs from the 2024 through 2026 model years, built between September 7, 2022 and June 9, 2026. Ford's internal number is 26C40. The company estimates 1% of them carry the condition, roughly 1,500 cars.

The remedy letters are scheduled for March 31, 2027, seven months after the letter warning owners the problem exists.

The Issue

A ground eyelet is the flat ring terminal at the end of a wire that bolts to the body or engine to complete a circuit. The engine compartment harness on this Mustang uses four of them, and each one grounds a different set of loads. Which functions an owner loses depends entirely on which eyelet breaks.

Ford's list covers a wide spread: loss of motive power, loss of the right headlamp, the left headlamp, or both, loss of the windshield washer pump, loss of air conditioning, and an engine cooling fan that stops running. The headlight and washer failures put the car out of compliance with FMVSS 108 and FMVSS 104, which is why this is filed as a noncompliance alongside the defect.

The cause traces to a change Ford made for the better. Beginning with 2024 model year production, heat shrink was added to the harness to protect the connections. On some builds the adhesive inside that heat shrink crept into the bolt-clearance envelope around the eyelet, so when the terminal was torqued down it bolted up bent rather than flat. An eyelet held in a slight permanent bend has a shorter fatigue life, and engine bay vibration works it until it fractures.

Ford introduced corrective actions in production on June 9, 2026. Cars built after that date are outside the population.

Affected Models

Model	Model years	Production dates	Units
Ford Mustang	2024-2026	Sep 7, 2022 - Jun 9, 2026	148,663

The recall covers the seventh-generation Mustang across its full run to date, and Ford draws no distinction by engine, trim or body style in its filing. The population begins with 2024 model year production because that is when the heat shrink entered the harness, and closes on the June 2026 production fix.

As with Ford's other August campaigns, these cars were not built in VIN order, so a VIN falling between two affected VINs proves nothing. The NHTSA lookup went live on August 28, 2026.

Chronology and Investigation

Ford's Electrical Distribution System team reported the durability failure to the Automotive Safety Office on June 4, 2026. Two eyelets on the test vehicle had broken and the car lost motive power during the test. Engineering had already worked the analysis far enough to conclude the same condition existed on cars coming off the line, and the stop-ship on 2026 Mustangs went out that day.

The concern reached Ford's Critical Concern Review Group on June 9, the same date the production correction took effect. June and July went to mapping the failure modes and working out how quickly a bent eyelet progresses to a fractured one.

On August 4, 2026, Ford reviewed global field data and found eight warranty claims that matched the condition, received between October 18, 2024 and August 4, 2026. Four of those eight came from cars less than three months into service. NHTSA had received zero owner questionnaires on the issue. The Field Review Committee approved the field action on August 18 and the Part 573 report was filed a week later.

Reported Incidents

Eight warranty claims across 148,663 vehicles and nearly two years is a thin field record, and Ford reports no accidents and no injuries.

The detail that carries weight is that half of those eight claims came from cars under three months old. A fatigue fracture that shows up that early suggests the eyelets in question started life bent enough to matter rather than wearing out over a normal service life. Ford's own engineers reached the recall through a durability test rather than through the field data, which is the sequence a manufacturer wants and the reason the count is as low as it is.

Remedy and Notification

Dealers replace all four engine compartment harness ground terminals with revised standoff eyelet pigtails at no charge. The replacement part uses a stepped-neck terminal geometry that Ford says eliminates the clamp-up interference and the out-of-plane bending stress that caused the original failure. Replacing all four rather than the one that broke is the right call given that any of the four can be the bent one.

Ford notified dealers on August 28, 2026, and VINs became searchable the same day. Interim owner letters mailed between August 31 and September 4. The letters that authorize the repair are scheduled for March 31, 2027.

Ford has not issued a do-not-drive or park-outside advisory, so affected cars stay on the road through the wait. Owners can reach Ford customer service at 1-866-436-7332 and should reference recall 26C40.

Symptoms to Watch For Before a Ground Eyelet Fractures

Ford lists three warnings in its filing, and all three are dashboard events rather than mechanical noises. A driver in a seven-month wait has a usable set of things to watch.

An illuminated check engine light. Named first in Ford's filing. A ground fault throws codes that look electrical rather than mechanical, so the shop diagnosis matters more than the light itself.

Instrument cluster warning messages. Messages about charging, lighting or climate that appear and clear on their own. An eyelet that has bent but not yet broken makes and loses contact with vibration.

An audible chime with no obvious cause. Ford calls this out specifically, and it tends to accompany the intermittent messages.

A headlamp that works intermittently. One side flickering, dropping out over bumps, or failing to light on a cold start. Two separate eyelets serve the left and right sides, so a single-side failure is the expected pattern.

Washer pump or air conditioning dropping out. A washer pump that does nothing when the stalk is pulled, or air conditioning that stops blowing cold with no refrigerant loss, both point at a lost ground rather than at the component.

A cooling fan that never comes on. The consequence here is not immediate but it compounds, since a car that cannot run its fan will build heat in traffic and on grades.

How Long Will the Recall Repair Take?

Replacing four ground pigtails is a modest job in isolation. The terminals are in the engine compartment, the pigtails splice into the existing harness, and the work is unbolting, splicing and re-torquing rather than pulling a harness. A booking of a few hours is a reasonable expectation once parts exist.

Parts are the whole constraint. Ford put remedy availability at March 2027 in its own filing, which means dealers spend the winter taking calls on a recall they cannot yet perform. Ford has published no labor time for 26C40.

Bottom Line

Ford caught this one the way the system is supposed to work. A durability test broke the part before customers did, engineering connected it to production the same day, and a stop-ship went out before a single additional car shipped. Eight warranty claims across 148,663 vehicles is the evidence that the field never got ahead of the engineering.

What owners are left with is a seven-month gap and a failure mode that can take a headlight out at night. A flickering headlamp, a chime with no source, or a cluster message that clears itself are all worth a dealer visit rather than a wait, because Ford's own list connects every one of them to an eyelet that has started to go.

Owners of a 2026 Mustang have a second campaign to check while they are in the lookup. Ford's piston recall, 26V548, covers 237 2026 Mustangs with the 2.3-liter EcoBoost and was filed the same day.

Find your Ford Mustang recall information: https://www.ford.com/support/recalls/