Sunday, October 2, 2022

MENU

Ask Dave: My microwave outlet is dead but all others are working. Why?

Dear Dave,
I have a Thor Hurricane M35. The microwave outlet is dead, but all other electrical outlets still work. Where do I start to locate the problem? GFIs have not tripped. Any help will be appreciated. Thank you. —Fred

Dear Fred,
Typically the outlet for the microwave would not be “ganged” to a Ground Fault Circuit Interrupter, rather a dedicated wire from the distribution center to the outlet. Below is a diagram from a Winnebago motorhome that has a similar distribution center and shows wiring for the microwave and the other outlets.

It might be hard to see; however, the microwave outlet is a dedicated 15-amp circuit breaker with a 14-2 wire coming off it. The wire goes to a 110-volt connection under the galley, then to a 110-volt connection under the stove, and then to the microwave outlet labeled RCP-2. No GFCI in the circuit!

Also on this load center is a 15-amp circuit breaker with 14-2 wire. This wire goes to a GFI-1 outlet in the bathroom, ganged to RCP-2 exterior, then goes to 110-volt connection under the right front room, then to 110v connection under the dinette, and finally to RCP-3 at the dinette.

Troubleshooting the dead microwave outlet

First, I would start with a Ground Fault Circuit Interrupter tester plugged into the outlet to verify if it has power or not. You can use a simple one available at any home improvement store or even Harbor Freight. I got mine at Home Depot.

Test the outlet to make sure it does not have power. If it does, then you have an issue with the microwave. If it does not have power, use a non-contact voltage tester to see if there is any voltage to the outlet. The non-contact voltage tester will indicate power within a 6″-8” distance so a wire could be disconnected but still show voltage. If this is the case, shut off the circuit breaker at the distribution center and pull the outlet out to inspect the wiring.

Assuming there is no power to the outlet, check the circuit breaker at the distribution center. You will probably not be able to use the non-contact voltage tester as it will indicate voltage from a close breaker, so that would need to be conducted with a multi-meter. However, you should be able to locate the wire coming off that circuit breaker and follow it with a non-contact voltage tester. As shown above in the Winnebago example, you might have a junction box in-line that could also be the issue. Using the tester, you can verify if there is power going to the junction box and then to the outlet.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

Read more from Dave here

HAVE A QUESTION FOR DAVE?

We have started a new forum link for Ask Dave. Please be as brief as possible. Attach a photo or two if it might help Dave with his response. Click to visit Dave’s forum. Or send your inquiries to him using the form below.

Click or drag a file to this area to upload.

##RVDT1813

Comments

Subscribe
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

7 Comments
Newest
Oldest
Inline Feedbacks
View all comments
Dennis
6 months ago

My 1999 Forest River Class A has a dedicated switch to choose EITHER the microwave or the electric water heater element. You can not run both at once. This rocker switch is located in the galley. (sorry, I used to own a 42′ triple engine cigarette boat) Perhaps their switch is not set correctly?

David
6 months ago

Our power to the microwave went out.
We also have a dishwasher in our Bounder and found out the microwave plug was connected to the dishwasher switch.
The dishwasher switch was turned off, when it , dishwasher, switch was turned on the microwave magically lit up.
So the dishwasher switch lit up the plug for the mucrowave.
Go figure!!!

martin a
6 months ago

I have a 30 amp Bigfoot travel trailer the microwave wouldnt work one day when setting up, breakers were all good, power everywhere else. Pulled the microwave out and it had become unplugged from the outlet in the enclosure. I used a couple of zip ties to lock it in the outlet. I dont like taking the microwave out. There is a separate switch that prevents the microwave and electric element of the hot water heater from being on at same time.

Steve
6 months ago

If the RV has a 50 amp service, be sure both legs of the service are hot at the RV panel. If one leg is not hot because of a faulty pedestal breaker, it may be that the microwave is on that leg and the problem would be at the pedestal.

DAVE TELENKO
6 months ago

Hey Dave, I found it very informative about using a non contact voltage tester. Great way to find a broken or disconnected wire!
Snoopy

Bob S
6 months ago

I had the same issue. My kitchen is in a slide-out, so there was a regular outlet in the basement, just behind the slide, used for an electrical disconnect. The microwave circuit ran through this outlet and the outlet had failed. I replaced it with a high quality outlet from the home improvement store and it has worked well ever since.

Steve
6 months ago
Reply to  Bob S

Yep, the outlets used in RVs are junk.

Sign up for the RVtravel Newsletter

Your information will *never* be shared or sold to a 3rd party.

Subscribe to our newsletter

Every Saturday and Sunday morning. Serving RVers for more than 20 years.