Electrical Resistance (Ohms)
Electrical resistance is how much a component opposes current flow, measured in ohms.
What is Electrical Resistance (Ohms)?
Sensors, coils and heaters have specified resistance values. High resistance in connections causes voltage drops. Measure resistance with the circuit disconnected. Ohm's law says voltage equals current times resistance, so even a small resistance can cause a large voltage drop at high current. Many sensors are diagnosed by comparing measured resistance with a table across temperatures. Connector resistance should be close to zero.
How it works
Resistance, voltage and current are linked by Ohm's law.
Why it matters for your car
Values outside specification point to faulty components. Temperature changes resistance, so compare at the right temperature.
Other terms
- AdBlue Crystallisation (Urea Deposits)
- All-Terrain Tyre (A/T)
- Belt Tensioner
- Blower Motor (Heater Fan)
- Car Shampoo
- Contact Cleaner (Electrical Cleaner)
- Engine Flush
- EV Charging Adapter
- EV Route Planner
- Front-Wheel Drive (FWD)
- Glow Plug Control Module
- Head Gasket
- Option Codes (Equipment Codes)
- Park Assist (Automatic Parking)
- Patina
- Preconditioning
- Reversing Camera
- Seatbelt (Safety Belt)
- Vehicle Registration Document
- Viscous Coupling