Amateur needs help with bathroom fan & light switch wiring

[Marbrus]

Hello all,

I'm hoping I could get some (much needed) help with my bathroom fan and light-switch wiring.
First off, I'm an amateur, but I've watching/reading as much as I can to understand electricity, but I think I need some expert advice, to untangle this mess.
If this is the wrong place, my apologies, I'll quietly delete my thread and move on.

The background: My bathroom light started to flicker and then would intermittently not work. Yes, I checked, changed the lighting fixture, and it was not the problem. Seems like it was loose/bad wiring. I stripped and re-wired the light-switch and it worked well for about a week, and then started to work on and off intermittently again
It feels like I need to go “further up the wiring in the wall” to see where the bad connection is. After removing the fan and light-switch and trying to pull out the junction box, I had even more question about the wiring. I have a feeling the previous owner was an amateur electrician, so I’m worried that there may be mistakes.

I see 3 main wiring feeds coming into the box. Each has a hot (black), neutral (white) and a ground??? (steel/red/copper?!?).

So let me start asking questions:
1) So, correct me if I’m wrong, I guess the 1st feed is for one power source, (say the fan), the 2nd feed is for the light, and I guess the 3rd would be to continue a feed to another place/room/etc.?
2) Is this OK, that the 3 neutrals are all just tied together?? Shouldn’t they be acting as return feeds? Shouldn’t this be wired differently?? Advice please.

I would really appreciate any help on this.
These pics, I hope help explain what I'm talking about.

Thanks everyone.

-Mac

 

[WorthFlorida]

You have a mix of aluminum and copper wire. Replace any outlet or switch with a stamp of CU/ALR (Copper/Aluminum) if the switch is only approved for CU (copper). Using aluminum wire on a copper only switch will loosen overtime and cause flickering and possible over heating.

All neutrals must be tied together. Each branch of the circuit needs a return path. Being a bathroom, is there an GFCI outlet?

What I see is the two cables, left (1) and center (2) are aluminum wire (notice the ground wires are silver). The right one (3) is copper. This was was added later on.

With aluminum wire, the wire nuts must use an approve wire nut with a special paste inside the wire nut to prevent corrosion. These are purple in color and are not cheap. My son's neighborhood and his home has aluminum wire so the local the Home Depot has them in stock. Maybe hard to find in some areas but there is always Amazon.

https://www.homedepot.com/p/IDEAL-Twister-Al-Cu-Wire-Connectors-Purple-10-Pack-30-1765S/202935623 or https://www.homedepot.com/p/AlumiConn-2-Port-Al-Cu-Wire-Connector-10-Pack-95015/204958912

The center cable red wire is probably on the switch going to the fan or light. Another picture further away to see what is an outlet and switch.

Aluminum wire must be used with outlet and switches approved for aluminum wire.
From a google search: Use CO/ALR switches/receptacles: these are specifically designed for aluminum wire. They have "CO/ALR" stamped on them somewhere. When you connect the wire, use a paste like Noalox (box stores sell it).

Leviton 15 Amp CO/ALR AC Quiet Toggle Switch, White R52-02651-02W - The Home Depot

The Leviton 15 Amp CO/ALR Single-Pole Grounding Toggle Switch is designed for use with aluminum or copper wiring. This convenient switch controls lighting from 1 location, making light operation more convenient. The single-pole design has a white color that coordinates with a variety of plate...

www.homedepot.com

Aluminum mixed with copper is a big subject but it's easier than you might think. If you have an outlet feed with aluminum and need to add another outlet down stream, use a CU/ALR outlet to transition from aluminum to copper using the four screw terminals on the outlet.