This post is the second in a five part series where I’m showing RV owners how to take a $7 multimeter from harbor freight and use it save $5,000 in their RV. A certain big box RV store near me is charging around a $500 minimum for mobile RV repairs.

So I thought as a certified mobile RV repair tech I’d show you 10 of the most common calls I get as a tech and reveal to you the secrets on how to fix them yourself. So you can keep your money in your pocket and your RV on the road.

You Got this.

AC Voltage

Last video we talked about the Dc voltage test on your multimeter. This video we’re cracking into the AC voltage test.

People who’ve taken RV Basics to Badass (my free RV beginners course) will know that there are two types of electricity in your RV.

AC and DC.

The DC power is the brains of the situation. It goes through your RV and tells things to turn on, but for the most part it isn’t actually powering any of your beefier appliances.

The AC power on the other hand is the muscle. It comes in to power our more power intensive appliances like our air conditioner, our microwave, and all of the outlets.

The DC power came from our batteries.

The AC power usually comes from plugging into a pedestal at a park. Any time you plug your RV in, that is to get AC power to the rig.

The AC power going through our RV is exactly the same as the AC power going through a house that you may be used to.

So while when we were working on the DC side of things we were looking for 12 V, on the AC side we’re looking for 120 V, just like in a house.

You may hear it called 110 or 115. We’ve just changed over the years how beefy we want our AC power to be. It used to be 110 and then 115 and now we work with 120. But older people who are set in their ways tend to call it 115. Its all the same thing.

Oh and by the way if you’re madly taking notes. I see you I love you. You can also just head over to RVRepairWoman.com/5000 and I have a workbook that will show you how to set up your meter for each test and walk you through all of the 10 calls in this series and how to solve them yourself.

You Got This.

But just like the DC voltage test, the AC voltage test is the test we use to find the AC power in the circuit.

AC Bob the electron is still trying to go over a mountain and through the woods to grandmothers house. But if he goes into the woods and never comes out then we know the woods is the source of our problem.

Same goes for a circuit.

If we can confirm that bob made it into a circuit board for instance, but never came out, then we know the circuit board is the source of our problem.

To get your meter ready for a Bob finding mission simply look at this section labeled ACV.

We do need to tell this meter, because it's not very sophisticated, roughly what range of AC volts we're looking for.

Like we said when it comes to AC voltage in RV’s we are usually looking for a number around 120V so we would set this meter to 200, because that’s the closest number it has to 120.

One last thing to to know about AC power before we jump in. AC power is so beefy that we like to give it back up plans on how to finish its job.

So you may have seen me draw a Dc circuit like this, just a big circle. With AC power we always give it an extra bonus path to make it back to ground. So that way if anything happened to the default path, there is a back up path.

The default path is usually called the neutral and the back up path is usually called the ground. But both have the same job.

And now we’re ready too….

ring ring

Oooo there’s my first call of the day.

Call 1

Customer: Help! Help! My microwave stopped working and it won’t turn on!

Me: I’m on my way.

Let’s talk about outlets in your RV and something called a GFCI or ground fault circuit interrupter.

GFCI’s are fancy outlets with a breaker built into them. Their whole job is to stop sending power out of the outlet if the draw on them gets too high.

That high draw can be from an appliance malfunctioning and pulling more power than it should or from something getting into the outlet and shorting it out.

In a residential house you’ll see these guys anywhere were water might be present. So in the kitchen, the bathroom, and any outside outlets.

If water were to get into the outlet it would be the equivalent of jamming a fork into the outlet.

https://www.youtube.com/watch?v=_6QsYTCA9BU

Not good.

So the GFCI is supposed to shut the outlet down the second that water gets into it.

While you should have multiple of these kinds of outlets all over your house in the RV you usually just have 1. And its usually hiding in the bathroom.

What they do in RV’s is take all of the outlets in your kitchen, your bathroom, and outside and wire them together with the outlet in your bathroom.

So if something goes wrong with ANY of these outlets, the GFCI in the bathroom could trip and you could lose power to about half of your RV.

Here’s how to test if your outlet is getting power.

Set your meter to AC volts, make sure you’re plugged into shore power and head over to one of your outlets in your kitchen. If you put your probes here and here, you should see a number in the realm of 120 V. This is the neutral path for the electricity.

If you put your probes here and here, you should also see a number in the realm of 120 volts. This is the back up ground path we talked about for the electricity.

Just for kicks and giggles go ahead and put both of your probes in the same hole here. You should see 0 volts, because your probes are in the same place, and we're measuring voltage difference across your probes. Remember that from the last video? See it all comes full circle.

So, even though there is power going to the outlet, you're not reading it because you have both of your probes in the same place.

Now put your probes back here and here. You should see 120 again. Now go to your bathroom and find your GFCI. There should be a button on it that says test. Hit that button and you should lose 120 at the outlet in your kitchen. Hit the button that says reset and you should get that 120 back.

Because all of these outlets are wired together it doesn’t even take the outlet getting wet to trip the GFCI. If you have your microwave, a hair dryer, and your fridge going on AC at the same time you can trip that breaker.

It acts the same as if you had all of those things plugged into the same outlet.

So if your outlets, your microwave, or your fridge on electric stop working, this GFCI is the first thing I want you to check.

ring ring

The calls never stop.

Call 2

Customer: Help! Help! I’m not getting any power to my rig. The pedestal seems melted so I don’t think its working!

Me: I’m on my way.

A couple of easy things about RV park pedestals before we even pull out the multimeter.

If a pedestal outlet ever looks melted, DO NOT plug into it. That melting means that this pedestal had a pretty major electrical problem at some point. It may have been the last customers fault. It may have been the parks fault. There isn’t great way of knowing.

What I do know is that I’m not taking the chance that it happens again with my RV. If I see a melted pedestal outlet, I’m going to the front office and requesting to be moved to a different spot.

You can be nice, you don’t have to be a Karen about it, but this is a hard and fast no for me.

It’s not a chance I’m willing to take.

Secondly I am never plugging my RV into any outlet without using something called an EMS or an electricity management system.

It's basically just a fancy surge protector that goes in-between the pedestal and the RV.

It will check to make sure the pedastal is wired correctly and giving you good power. EMS’s usually cost $200 to $400. And Investing in one will protect not only your RV and all the appliances in it, but also your life.

If an AC power surge goes through your RV unprotected it could damage every wire and appliance in your rig.

Like honestly I could stop the whole save $5000 series right here with that piece of advice.

Use an EMS.

But if you still think something is fishy with your pedestal here is how to test it with your multimeter.

Set your meter to AC volts and head over to your outlet. If you're looking at a 30 amp outlet here is how to test it. 

On a 50 amp outlet you are actually combining two outlets into one. So you get two sources of 120 V. In the industry we call these two sources of 120 your two hot legs.

Here is out to test a 50 amp outlet.

That’s another 2 calls down and $2500 saved. If you want to learn the hands down #1 most common call I get and how to fix it yourself check out this video when it comes out.