Multimeter tutorial

[cpaharley2008]

For those who may need it….

 

[jennykatz]

elec

thanks

 

[EDarby]

That was great,thanks!

For those who may need it….

 

[Jubal]

Also a good idea to read the instruction manual came with you multimeter.

 

[CharlesPou]

thanks for posting vid, but after watching it, can I use a multimeter?, probably not, sorry

 

[Ron in BC]

Well if reading simple voltage, which is one of the most important tools for trouble shooting, is too much for you there's a simple probe with a light bulb. Not as good but at least let's you determine terminal to terminal where the power is and isn't.

It always amazes me the number of folks that have posted "no power". My brain automatically says "no power where?" Knowing where the power is and isn't is does most of the job of trouble shooting the situation.

Ron

 

[CharlesPou]

hello Ron, I have the test light too, but never use it. sorry, I'm a little slow with electricity. I've often managed to fix things without using a multi-meter or test light. maybe if I knew how to use them, it would be helpful. I've looked at how to use them many times, but when something needs to be fixed, I never think about it, and often get the job done anyway.

just recently I repaired my home microwave, over 20 years old. I went online, did a little reading, appeared most likely was one of 3 small switches that were mechanically controlled by the door. I ordered the switches $20, replaced them, and saved $400 over buying a new built-in microwave. never occurred to me to use a multi-meter or test light. I have many stories like that to tell, don't want to bore, hopefully you get the idea. cheers

 

[Ron in BC]

Many of the problems posted relate to DC devices not working. Many times the person doesn't have a clue whats wrong or where to start. Using a test light or multimeter, starting from a known source of power, eg. the battery terminals and proceeding step by step until the power disappears pinpoints the problem.

That's presuming of course that the battery reading shows it isn't the problem.

Many times the problem is something like a switch not turned on. Power at one terminal, no power at the other, hmm, what could be wrong?

Yes, I've fixed two microwaves in the past year. Didn't use a multimeter on either. But for the trailer, not being able to test for 12 volts, is making yourself less self sufficient and needlessly inconveniencing yourself if you have a problem and no one to help you with it.

Ron

 

[Ronn]

just recently I repaired my home microwave, over 20 years old. I went online, did a little reading, appeared most likely was one of 3 small switches that were mechanically controlled by the door. I ordered the switches $20, replaced them, and saved $400 over buying a new built-in microwave. never occurred to me to use a multi-meter or test light. I have many stories like that to tell, don't want to bore, hopefully you get the idea. cheers

Great story, I just replaced my 13 year old microwave. Listed $500 Best Buy $254 all inclusive (same brand and specs, but mounted different than the old one - new holes and different wall bracket height).

My switches were fine, the door latches just wouldn't trigger the switches. Triggered one, but wouldn't trigger the other two. I messed with it every which way and finally came to the conclusion either fix it or break it. The $254 tells the story of how that worked out.

I have no idea how they can sell this for $254, it likely would have cost that to have it serviced.

 

[vermilye]

I taught 100's of students electrical troubleshooting over the years with theatre lighting systems. The best & fastest procedure was to first check the obvious (only learned by many troubleshooting sessions).

If that didn't solve the problem, divide the circuit in the middle. If it good, divide what is down the line from the middle in half & check again, Same going the other way - if the middle is bad, go half way back & check again.

 

[CharlesPou]

another story: I had used 2004 Casita Deluxe 17, purchased 2006, sold 2018 before I picked up my new 2018 Escape 21. the Casita was a great trailer for approx 12 years I had it, but had various problems over the years, I was able to fix every issue.

one time the microwave quit working, I know another microwave story. Casita has a great forum, just like Escape, so I started a thread. immediately I got lots of suggestions to get a multimeter and start trouble shooting. then as now, I don't really know how to trouble shoot with a multimeter. so, I removed the facade (not that easy), pulled out the microwave, and it was unplugged. another fix without using a multimeter. cheers

 

[Greg A]

Jon’s “first check the obvious” has solved a ton of electrical issues. In IT, when we got a call that a system had died, we would direct them to check if it was unplugged. This solved many dead systems, and we discovered it is due to the cleaning crews unplugging to plug in their vacuum.
I’ve noticed a battery switch being off on these trailers is accounting for quite a few electrical issues. Always start there and then move to the next item.

 

[sherminator]

I've done my share of professional troubleshooting also - mostly electrical, but some programming, some hydraulic, less mechanical. My order:
1) if you've seen the symptoms before, it is probably the same cause as last time
2) is it powered on?
3) if it has some kind of control program, reboot it - hard reboot preferred
4) if you don't have a good idea of what the problem is, and there are some parts of the system that are quick & easy to check, do those checks in order of how quickly you can do them. You might get lucky!
5) If the above don't work, use the divide and conquer method Jon pointed out.

 

[dbailey]

My debugging methods are well exemplified with an example from last week... The 12v outlet under the passenger side dinette wasn't working.
1. test for 12v at the outlet contacts. Nothing.
2. test for 12v at the wires connecting to the outlet. Nothing.
3. test for 12v at the wires leaving the converter. Power there.
4. decide I don't need that outlet after all, walk away.

 

[gbaglo]

;D Good work!

 

[tdf-texas]

My debugging methods are well exemplified with an example from last week... The 12v outlet under the passenger side dinette wasn't working.
1. test for 12v at the outlet contacts. Nothing.
2. test for 12v at the wires connecting to the outlet. Nothing.
3. test for 12v at the wires leaving the converter. Power there.
4. decide I don't need that outlet after all, walk away.

Now that's funny!

Of course, the first electrical problem with my trailer ended up with most of the trailer being rewired to my specs. I just couldn't have walked away.

 

[CharlesPou]

hello tdf, some think perfection is the enemy of good, cheers

 

[CharlesPou]

I used a multi-meter today, 1st time ever. was kind of cool, yeah! cpa, thanks for posting vid, some of it must have soaked in. cheers

 

[Rossue2]

hello tdf, some think perfection is the enemy of good, cheers

So many espouse the saying "Good enough for Government work". Others have an insight and talent to do much better and that inspires me!