You can measure directly with an Ohm Meter, often combined with a Volt Meter. Or you can measure the voltage across the resistance and the current to calculate resistance as Current divided by Voltage.
First you need to know the value of the resistor. Follow the link for a handy resistor calculator After determining the value of your resistor simply test the resistor with an ohmmeter to see if it is at true value. General use should be within + or - 5%
No, the resistance of a resistor remains the same whether it is connected to a power source or tested out of circuit. The resistance value is an intrinsic property of the resistor and does not change based on the external conditions.
Resistor
You can keep a resistor at a constant temperature by using a heat sink to dissipate excess heat generated by the resistor. This helps maintain a stable operating temperature and prevent overheating. Additionally, ensuring proper ventilation and using a resistor with a high power rating can also help regulate its temperature.
Resistor have a definite function in circuits and because every resistor disspates power, it is not included in the circuit without good reason. Some smoke detectors have electronic circuits in them, and these would have resistors, but it is not possible to be more specific.
yes resistor can check in CRO.Using an probes we can check it. CRO shows the waveform.
There is really no method to "check" the resistor, text by substitution.
Check the resistor if it only works on high Check the resistor if it only works on high Check the resistor if it only works on high
Check the fuse Check the relay Check the switch Check the resistor
Since you're checking the resistor, I would assume you checked the fuse/relay for the blower motor. If not check that. If you have then there would be an open wire between the relay and the resistor.
using the color coding method
If it's a fan speed issue check the blower motor resistor & the blower motor. Check the plugs at the resistor and blower motor for burn marks also.
Check the resistance on the blower motor.
use a merger tester, if there are no indication to certain number of ohmic (50 M), that is mean resistor is open.
Before taking the dash apart check the resistor. I have a 97 Dakota & it is located under the cowl. That resistor controls the fan speeds. You can check the switch using the resistor connecter. Pull connecter off resistor & use a 12 volt test light. Turn ign on & check for voltage at connecter on each fan speed. Have voltage then it is the resister or fan. (you can run a jumper wire from battery to fan to check it) No voltage then you go to the switch/wires etc. 95% of time it is the resistor.
Fan motor? Check fuse, Check resistor pack at fan motor Check coolant level
Check the fuse. Check the blower speed resistor. Check the blower speed control switch.