2021 Ford F-150: Rodent or squirrel ate wiring insulation
Common wear/failure (not a recall)
Symptoms
Owners of the 2021 F-150 report: rodent or squirrel ate wiring insulation. CarComplaints.com lists 1 owner complaints, average mileage 2,900 miles.
NHTSA has 173 owner complaints for the 2021 F-150 in this area. Examples:
- NHTSA complaint ODI #11769880 (filed 10/08/2026): “While driving truck, it had an electrical fritz that caused the car to become undrivable, with systems not responding. when stopped to power cycle, the car would accessory on but not attempt to start. the horn would go off randomly. was able to manually put th…”
- NHTSA complaint ODI #11768043 (filed 09/30/2026): “This vehicle was purchased new. it currently has about 56000 miles. over time there have been numerous incidents where the battery was suddenly dead. the dealer repeatedly replaced the battery with out addressing the cause. this was done under warranty until r…”
Likely causes
Sources do not establish a single root cause; diagnosis is needed. Owner-reported fixes are listed below.
Fix, in plain English
Most common owner-reported solutions on CarComplaints.com: none clearly reported. Check for open recalls and extended warranty coverage with a dealer before paying out of pocket.
DIY difficulty: Moderate
Finding and splicing chewed wiring is doable with a multimeter and patience but can be time-consuming; harness replacement is pro work. (Our assessment.)
Cost
CarComplaints.com owners report a typical repair cost of about $580 (owner-reported average, not a quote).
Typical parts (search links, no affiliate codes)
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