Investigations
HVAC Switch Failures
NHTSA Engineering Analysis EA10003 - closed, opened 2010-04-13.
NHTSA investigation EA10003 is a Engineering Analysis opened on 2010-04-13 and currently closed. The subject is tracked inside the Office of Defects Investigation queue. Latest activity on this investigation was logged on 2012-03-05 - NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
An Engineering Analysis like EA10003 is the deeper technical phase that follows a PE. NHTSA requests design, warranty, and field-failure data from the manufacturer, conducts its own testing when needed, and determines whether the evidence supports a safety defect finding that would compel a recall.
Investigators summarized the matter as follows: "This investigation was opened based on one complaint and reports from four transportation fleets alleging 182 blower motor control switch failures. ODI was concerned that these melting and burning switches could lead to..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time.
Investigation Summary
This investigation was opened based on one complaint and reports from four transportation fleets alleging 182 blower motor control switch failures. ODI was concerned that these melting and burning switches could lead to an open flame that could spread throughout the vehicle. After a comprehensive review of all data related to overheating blower motor control switches in the subject vehicles, ODI did not identify the existence of a safety defect trend. ODI reviewed 1,036 complaints, claims, and field reports of failed blower motor control switches and determined that only two fires were likely to have been caused by a failing subject blower motor control switch. This represents a failure rate of 0.2 R/100K on a population of 1,076,975 vehicles that have been in service for up to 14 years. ODI has found that when the subject switches do fail and begin to melt, they are constructed in a manner that typically prevents the failing switch from igniting and developing into an open flame. Ford Motor Company has agreed to take two actions to further reduce the likelihood an overheated blower motor switch in the subject vehicles. Ford informed ODI that it has implemented a series of design changes to the subject switch that will help prevent it from developing internal high resistance short circuits. Ford has also informed ODI that it would release a Technical Service Bulletin (TSB-11-11-21) instructing subject vehicle owners to replace the electrical connector at the same time a failed switch is replaced. In light of the low rate of failure resulting in open flame and fire spread on the subject vehicles, and Ford's actions to reduce the likelihood of a switch failure through switch design changes and a TSB, further use of agency resources does not appear to be warranted. The closing of this investigation does not constitute a finding by NHTSA that no safety-related defect exists. The agency reserves the right to take further action if warranted by the circumstances. The ODI
About This Investigation Type
An Engineering Analysis (EA) is the in-depth phase following a Preliminary Evaluation. NHTSA engineers conduct testing, collect data from manufacturers, and perform detailed technical analysis to determine whether a safety defect exists. An EA may lead to a voluntary recall by the manufacturer or, in rare cases, a mandatory recall order.
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. about how PlainCars sources NHTSA data.
Read our methodology - how this data is sourced, computed, and verified.