An inductive load is any thing with a coil of wire, relay, starter solenoids, motors, an ignition coil is a good example of this. With only a 10:1 turns ratio from secondary to primary, the instant the circuit is broken 12V at the primary can generate 40KV at the secondary, all deals with rate of change of the current flow. Ha, basic stuff, that collapse generates a spark across point contact relays contacts, and the arc causes contact damage, actually the best material to use is tungsten, it can take the heat. Another hazard is when the contacts close with an incandescent bulb, cold resistance is very low resulting in a surge current that greatly exceeds the contact current rating. Only good engineers know this stuff.
Silver is the worst plated on a copper contact, idiots just read the conductivity of these good metals, but they cannot take the heat. A$$holes for lack of a better word, specify this because of the higher conductivity, think they can get by with a smaller contact, while tungsten can take the heat, it does have a greater resistance, solution is simple, use a larger contact. But then you have more a$$holes called bean counters. But this is only one of the problems.
The key problem is voltage drops across what you would expect to be a short circuit with zero ohms of resistance. The most negative point in a vehicle is the negative battery post, not the terminal that wraps around it, but the post itself. And likewise the most positive point in the vehicle is the positive post of that same battery.
Using these points as a reference and with now a very inexpensive VOM can check for voltage drops, a key ground point for practically all the vehicle electronics is the engine block itself. But too measure voltage drops, need a large current flowing, easy on a vehicle, switch on the headlamps, blower motor, rear window defroster, plenty of loads.
In my Cruze, with the black lead connected to the negative post of the battery, red lead on the engine block, the block was over 2 volts more positive, by working backwards, found the major voltage drop to be between the exposed end of the negative battery cable at the radiator ground point and the terminal of the negative battery post clamp. Took this apart to see bare corroded copper wire inside of that negative battery clamp. Drilled a hole where that crimp is so I could pull out the cable from the clamp, cleaned it, and with a propane torch, securely soldered that connection. Putting about 70 amps of current through it, that voltage drop changes from over 2 volts down to about 16 millivolts.
Working on vehicle electrical is always awkward to say the least, no points to measure, for a wire need a stick pin to make contact, but put a dab of RTV on it, or moisture will get in an corrode it.
For that ignition relay, had to use male and female 3/16" terminals plugged into the PCB board with the relay hanging on to it, four pins. With ignition on, was measuring over a volt across closed contacts, not good, and this voltage would change whenever I would switch the ignition on and off, erratic contacts.
To ease matters, pull all the relays out on my workbench energized the relays with a 12V supply and ran a constant current of ten amps through each one and measured the voltage drop, the rest were good, but for how long.
Really feel DRL's are a stupid safety feature, when conditions were right, we use to have brains to switch on our headlamps. Using lots of point contact relays for this "feature", and with a dirty contact, can get no headlamps at all, not very smart from my experience.
Ha, back in the 60's was working with Bell labs on the development of touch ton, they had literally thousands of stepping switches and point contact relays with 24/7 crews constantly reburnishing switch contacts. Solid state could be switched zillions of times without failure, and saved the phone companies millions in labor charges. But what did they do? Charge a lot more for touch tone.
Use to working with crooks.
