Alright, today on Repairs 101 we’re going to look at digital multimeters as well as analog meters. And a bunch of tests that you can perform using them.
Today’s episode of Repairs 101 was sponsored by Princess Auto.
Multi function
Now, a multimeter can be analog or digital and generally tests things like voltage, current, and resistance. But can have a number of additional test points including this setting for household batteries. Whether your batteries are big and heavy or tiny and light a multimeter can diagnose its performance.
DC
Here I am doing a surface charge test on six and twelve volt configurations. If you have smoke detectors that run on nine volt batteries it’s a good idea to test them periodically. This little flashlight has a carriage inside for three AAA batteries carrying 4.5 volts or more.
AC
Switch the dial to measure AC volts for this next test. Then place the red probe in the smallest hole. The black probe can find ground through the neutral terminal or through the ground pin. Alright same deal with this two prong extension cord. The small blade goes in the hot slot, so check for continuity in each of the plugs.
Stray current in an engine can be disastrous. It can result in degrading liners, oil coolers, radiators, heat exchangers, extreme aluminum corrosion, water pump, and head gasket failure just to name a few things.
Under the hood
For this next test, switch the positive wire to the Ohm socket. Put the red probe on the center terminal and ground the black one against the threads of the casing. Continuity tests will prove these automotive fuses are still serviceable. Automotive fuses can also be tested from the top, like this.
Or set the dial to DC volts. Ground the black probe and check for voltage at the top of the fuse. Lightbulbs tests the same as a glass fuse. Check the resistance or the continuity between the center post and the threaded case.
Shielded cable
You can check shielded cable like on this VHF radio antenna and check the shield as well. Sparkplugs have a center electrode that carries current to the gap where it jumps across to make a spark. Alright, I gotta go walk my dog.
