Blower Motor Circuit Short to Ground
The B2470 code indicates that the Body Control Module (BCM) or HVAC control module has detected a short to ground in the blower motor control circuit. This prevents proper fan speed regulation, potentially leaving the blower inoperative, running at full speed only, or blowing the circuit fuse.
1. Commonly Affected Makes
2. Most Common Causes
- Chafed or pinched blower motor control circuit wiring shorting to chassis ground
- Blower motor resistor or control module internally shorted
- Blower motor with internal winding short to the housing
- Corroded, dirty, or bent terminals in the control circuit connectors
- Failed BCM or HVAC module output driver
3. Symptoms You Will Notice
- Blower motor does not operate at all
- Blower motor runs only at full speed regardless of fan setting
- Blower motor fuse blows repeatedly
4. Step-by-Step Diagnosis
Check for blown blower motor fuse and replace if necessary
Inspect blower motor control circuit wiring for chafing or pinching against chassis
Test blower motor resistor/module for internal short to ground
Check blower motor for winding short to housing using an ohmmeter
Inspect connectors for corrosion, dirt, or bent pins; clean or replace as needed
If all else is good, test BCM/HVAC module output driver per service manual
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the HVAC blower may not work properly, affecting defrosting and cabin comfort. If the fuse keeps blowing, avoid using the blower to prevent further electrical issues.
How much does it cost to fix?▼
Typically $100–$400, depending on the root cause. A blower motor resistor replacement is on the lower end, while a BCM replacement can be higher.