Troubleshooting wall outlet

Hi all.
At our ADU there is a dead bathroom wall outlet. Son lives there so of course, every time he needs to trim his beard he comes to our place.
Inspector did full run before purchase and mentioned that several outlets in ADU were wired backwards. That was fixed ever since.
This is the last non functional outlet in ADU. Not a CGFI outlet.
It is few inches away from light switch that operates light and fan. Light and fan work fine.
I bought receptacle tester yesterday and plugged it in. Nothing. Not a single light came up on it, switches on or off. Figures, it is not controlled by the switch.
I did not plug multimeter in yet.
What do I look for when I start tearing that outlet apart? Of course, clearly visible damage or lose contact. But what if all looks fine?
It's 2 bedroom ADU on the 2nd floor, so plan is to look around for CGFI that might be lurking somewhere just for that outlet. Son is not using bedroom across the hall from bathroom, maybe there is a whole circuit, that is not working, with CGFI.
Any other suggestions?
Please, keep in mind I "get it" as far as green, black and white, but talking "load" and other electrical lingo is beyond me. I need it simple and seriously do not want to pay electrician to fix a receptacle.
Thank you.

 

You don't say when the ADU was built, but unless it's quite old it should have GFCI for bathroom. It may be located elsewhere, or may even be a GFCI circuit breaker.

If you don't find one, then first step should be to pull the receptacle out and check the connections. You have to be careful, and may want to turn off all the power to the ADU since you can't be sure which breaker controls that receptacle. If you don't turn off all the power, be careful since a loose connection could cause arcing or give you a shock.

Check for bad connections at the receptacle. If all is good there, then you have to find where the wires for that receptacle come from. Pretty good chance it's the fan/light switch, so next step would be to pull that out and check all the connections there, including wire nutted connections.

If you have attic access above, you may be able to physically trace the cable coming from the receptacle and identify where it goes.

 

ADU is from around 2005. Reasonably new then. I'll look downstairs on main panel. It's - as usual - weird on wiring. Suddenly, all garage lights and openers went out, as in - no power. Took us 30 minutes to find out that it was a CGFI OUTSIDE the structure, on a wall. One of them weather cover duplexes.
So who knows. I'll keep looking. Electricians have their ways of complicating owner's life.

 

One would think bathroom light/fan switch be on same breaker as outlet, right? As fan and light work just fine. Outlet is literally 2 inches away.

 

Absolutely not! The receptacle is required to be on a 20 amp circuit, the lights are not. Also, newest code required lighting to be AFCI protected while the bathroom receptacle does not. I normally will wire the bathroom receptacle on its own circuit and the lights on some other 15 amp circuit.

Pull out the outlet and see if you have power between hot (black) and neutral (white). Also check if you have anything between hot and ground (should be 120v), and neutral and ground (should be continuity/ohms). If you get nothing between all points you will need to start back tracking. If there is not a GFCI breaker in the panel there is a GFCI elsewhere since you said that the non-working outlet is not a GFCI. My first guess would be in another bathroom.

 

I hate it when a GFCI is installed like that, it just makes no sense, but quite often is done that way. By the way, the garage lights aren't even required to be GFCI protected. It's just poor design and probably on the part of the guy doing the job. I suspect you'll eventually find an equally poor location for another GFCI device controlling the bathroom receptacle that has tripped.

 

Hate to sound like an idiot but what is an ADU?

 

Thank you for asking. I thought I was the only one who was stumped. I had to Google it. Accessory Dwelling Unit

 

Fixed it.
I was doing number 1 in garage bathroom, right below the one in question, and it had breaker outlet. GFCI, right? So I stuck my voltmeter into it and it was dead too. Pressed red button and magic happened. I think garage door installers iffed it up when they did their thing. They had power tools plugged in.

 

Glad you found it.

My advice in post # 5:

 

No, not RIGHT! A GFCI receptacle IS NOT a breaker outlet. A GFCI receptacle does not trip on overloads, but on a ground fault.

 

ADU = Additional Dwelling Unit, aka Mother in Law Quarters. The way it was, they bought the land, built ADU = 2 bedroom apartment with garages and lived there, while building the main house. Now my son "dwells" there.
Have no doubt we'll find some perks. So far, I had all kinds of electrical mind weirdness seen. GFCIs in places no one would have thought of. Or, all black or all white wires in wall outlets or light switches. Or, for that matter, all ribbed.

 

The wires were all ribbed? They didn't wire the switches and receptacles with lamp cord, did they?