10.1.3. Measurement of resistance
Measurement of resistance
Before check of resistance it is necessary to be convinced that on a detail to which the ohmmeter is connected there is no tension. Always therefore to disconnect plugs, to switch off ignition, to remove conducting or the device, to disconnect the rechargeable battery. Otherwise the measuring device will be damaged.
The ohmmeter is connected to two contacts of the consumer or both ends of electrical wire. At the same time polarity (±) does not matter.
Measurement of resistance in the car is carried out in two cases:
– control of resistance or the detail established in a chain;
– "conductivity" of the conductor, sensor or coil. At the same time existence of break in a chain because of which the block which is in it cannot work is checked. For measurement the ohmmeter is connected to both ends of the conductor. If resistance makes 0 Ohms, then "conductivity" is. It means that the electrical wiring is serviceable. At break in the conductor the measuring device shows infinity.