microwave circuit problem

[slouman]

Well, folks, all was well until microwave stopped today while the DW was heating supper. It has been working fine since we took delivery in February. Now, all of a sudden, it quit in the middle of the heat cycle and seemed to have no power at all (all indicator lights off).

My first inclination was that circuit breaker blew for some reason. Checked breaker and not tripped. Then checked voltage at recepticle where microwave plugged in. Voltage read about 80 volts AC. Went back to breaker and voltage measures 115 vac coming out of the breaker.

So far I have been unable to get inside the sealed recepticle to check voltage on the actual wire thinking maybe something is loose but I'm wondering if anybody else has any ideas. At this point it seems the problem will be either 1) loose wire at recepticle 2) broken wire somewhere 3) loose wire in panel box.

Just to verify microwave is not the problem I plugged it into a known working recepticle and all worked well. It quit because of low voltage.

What do you think? I have the skills to trouble shoot the circuit IF I can get to things but if you have a good idea of where to start it would help. I hate to wait until the end of the summer when I'll be near the CR plant to get it repaired.

Thanks for any input.

[Stan]

Is the m/w on it's own circuit? If not, what voltage reading do you get on the other outlets on the same circuit. That might steer you to a location. Other things to check...water in junction boxes under slides.

[FFFord]

Check the voltage to ground, if it is the same as at your breaker, then you may have a loose neutral in the circuit. Check each receptacle in the circuit, which may isolate the loose wire. On most RV's, the "romex" wiring is just pushed into pins on the back side of the receptacle, by the rear cover, which can vibrate loose.Make sure to turn off the power, before pushing the wire back into the pins.

[cwit]

With 2 posts on electric problems I would check all conections in panel box. Hot, nuturals and grounds. Now go from there if fault not found.

[slouman]

Microwave is on a dedicated circuit. Nothing else on circuit.

I should have mentioned this is a Rushmore 35CK and the microwave is mounted on the kitchen slide. I'm wondering if the wiring runs directly from the breaker box to the recepticle or if there is some kind of junction box to accomodate the slide. Anybody know?

As mentioned in original post I'll have more time to troubleshoot upon arrival at destination later in the week. Just trying to gather as much info ahed of time as to circuit setup. I hate to make a warranty claim for a simple loose connection.

Thanks for all the replies.

[Stan]

As mentioned above, look for grey junction boxes under the kitchen slide. I have (as have others) found water in these Jboxes.

[slouman]

Thanks, Stan ... I found the junction boxes you mentioned but they were not located where I expected them to be. It appears the feed wires from the junction box are a different type wire (more flexible) than the "romex" at the recepticle. Sure hope there is not a splice in the slide wall that turns out to be the problem.

Not going to do any more troubleshooting until I get to destination in a few days because rain coming here today. I can always use microwave with an extension cord for a time or two.

Thanks for all the ideas, folks.

[slouman]

Here's an update for anybody who might be interested. Today I had some time and checked the wiring at the above mentioned junction box. No problem found with correct voltage everywhere. I then took the wall receptacle out and checked voltage again. Correct voltage on the wire itself so reseated wires (knife type connections) and problem seemed solved. BUT, after I reinstalled the receptacle in the wall the problem reoccurred. I cut off short piece of wire and reinstalled in the receptacle. Same result ... low voltage again. My conclusion is that the "hot" wire is broken somewhere in the wall itself (my worst fear). It appears that romex section runs to another junction box behind the stove but I'm not getting into that. The unit is still under warranty and I'll take it to the factory in a couple of months since I'll be going that way anyhow. In the meantime I can still use microwave with an extension cord (yes, it's heavy enough) and keep on going. The resolution does not seem to be a big project but it's just something I don't want to tackle and create questionable warranty issues.

Thanks again for all your input.

[Monty]

Personally, I am not a big fan of the "press in" wiring connections (which is what I assume you mean by knife type connection). They don't always make a good contact. If there is an option to screw the wire down, I would give that a try. Could be a short in the receptacle where the hot wire is making contact.

[slouman]

PROBLEM FOUND! I went back to the junction box under the slide that I supposedly checked yesterday and something just did not look right so I went to take off the wire nut from the hot wire. Turns out the wire nut was melted (could not see that without taking elect tape off) indicating the connection was bad. Had only checked by probing load side of wire nut yesterday so must assume moving it around made slight connection. Cut off wires and reconnected with new wire nut. PROBLEM SOLVED! Now I feel kinda foolish but at least didn't call for warranty repair unnecessarily.

I agree with you about the press in receptacles. I had already redone that yesterday but there was no option to screw down. If they had a receptacle box in the wall I would replace it with a different type but at least it's sealed in the wall.

Thanks again, everybody, for the discussion.