Check The Resistance In A Circuit Using An Ohm Meter

CHECK THE RESISTANCE IN A CIRCUIT USING AN OHM METER






NOTE: This is not the best way of checking for an open ground circuit. When checking for an open in a ground circuit, perform the Check a Ground Circuit for an Open Using a 12-Volt Test Light diagnostic procedure Check A Ground Circuit For An Open Using A 12-Volt Test Light.

1. Turn the ignition off.
2. Disconnect the wire harness connectors of the components that contain the circuit suspected as being open.

NOTE: Check connectors - Clean/repair as necessary.

3. At this time leave all in-line connectors connected.

NOTE: Before measuring the resistance of any circuit, first measure the resistance between the two leads of the multimeter. Take this value and subtract it from the value recorded when measuring the resistance of the circuit being checked. The leads of the meter can add up to or over 0.5 of an Ohm of resistance.

4. With the component wire harness connectors disconnected, use a multimeter set to Ohms (Ω), and measure the resistance of the circuit.
5. Use one lead of the meter and probe the circuit in one harness connector.
6. Use the other lead of the meter and probe the same circuit in the other harness connector.

Is the resistance in the circuit below 20k Ohms?

Yes

- Repair the excessive resistance in the circuit between the two wire harness connectors. Using the wiring application as a guide, trace the circuit and check for any in-line connectors where the open or excessive resistance could occur.
- One way to help isolate the open is to disconnect any in-line connectors and measure the resistance from one side of the in-line connector to the matching component harness connector. If the open or excessive resistance is not present, the open or excessive resistance is on the other side of the in-line connector

No

- The circuit does not contain any excessive resistance or the condition that originally caused the excessive resistance may not be present at this time. Continue to measure the resistance of the circuit, wiggle the wire harness and connectors to check for an intermittent open or poor connection.
- Use the wiring application as a guide to trace the circuits and look for any in-line connectors where the open could occur intermittently.
- Look for any chafed, pierced, pinched, or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related wire harness connectors.
- Perform any Technical Service Bulletins (TSBs) that may apply.