B1841: Front Wiper Motor Power Circuit Open
Diagnostic trouble code B1841 indicates that the Body Control Module (BCM) or wiper control module has detected an open circuit in the power supply to the front wiper motor. This means battery voltage is not reaching the wiper motor when activation is requested, preventing the wipers from operating properly or at all.
1. Commonly Affected Makes
2. Most Common Causes
- Blown fuse in the front wiper circuit
- Damaged, corroded, or disconnected wiring between the BCM/relay and the wiper motor
- Faulty front wiper relay
- Open internal winding in the front wiper motor
- Loose wiper motor connector or damaged terminals
- Internal BCM failure in the power output driver
3. Symptoms You Will Notice
- Front wipers do not work at all
- Wipers operate intermittently or only on certain speeds
- Wipers stop working mid-cycle
4. Step-by-Step Diagnosis
Check and test the wiper system fuse(s) with a multimeter; replace if blown.
Inspect the wiper relay for proper operation; swap with a known-good relay if possible.
Visually inspect wiring and connectors from the BCM/relay to the wiper motor for damage, corrosion, or looseness.
Test for battery voltage at the wiper motor connector with the wipers commanded ON.
If voltage is present, test the wiper motor ground and motor internal resistance; replace motor if open.
If no voltage at the motor and all wiring/relays are good, suspect a faulty BCM and perform further BCM diagnostics.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but driving without functioning wipers in rain or snow is dangerous. The vehicle remains drivable, but wiper operation is compromised.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A blown fuse is cheap, while a BCM replacement can be more expensive.