Troubleshooting question: A few days ago 15 amp AFCI breaker tripped, so went down to basement and flipped it back on, that immediately tripped it again. Therefore, went back up to the bedroom and bathroom that breaker is assigned to and turned everything off and unplugged everything from outlets; went back and flipped it back on and it was good it stayed on. However, as soon as I turn on any of the lights it trips off again. All of the outlets work, tested it with a table lamp.

However, as soon as I turn the any of the light switches it trips again. There are total of 5 switches that cause breaker to trip; one controls bedroom celling fan light the other the ceiling fan, another is hallway light, another bathroom vanity light and last one is for bathroom fan/light. No matter which switch of those 5 I turn on it trips the breaker.

So next thing I did was check the breaker, breaker is good. Then I checked all the switches and switches are good. Then I looked at wiring of all the fixtures and everything seemed firmly in place, nothing melted, nothing weird to my amateur eyes. Therefore next I started disconnecting each fixture and after disconnecting one I would check if the I could turn on any of the other fixtures and after going through all of them nothing changed as soon as I would flip the switch it would pop the breaker.

Now interestingly enough the ceiling fan would work on slowest setting, it would not trip the breaker. However, as soon as I would flip any of the other lights on or increase the speed on the fan it would trip the breaker.

That gave an idea so I took a simple single light bulb fixture and wired it to each of the fixtures wiring first with a 60 w bulb then with a 13W bulb but still not luck of narrowing down the issue, each time I would turn on the light it would trip the breaker.

Any ideas what could be causing this? I would appreciate any help or advice as I am going crazy right now. The house was built in 2010 in Black Hawk County Iowa, it passed all inspection as far as I know. The contractor that built my house is not answering my phone calls. Thank you in advance.

I would try a different breaker. Its possible something in that one is messed up. Also have you been in the attic to check for a possible leak?

Bet a pizza that circuit runs.

From breaker to an outlet in the room, from that outlet to other outlets, to the switches. The last outlet in the circuit is probably the one closest to the switches, which are probably back to back.

If that is correct, the fault will be in the connection at the outlet of the cable from the outlet to the switches.

Thank you for the answers. I did check the breaker it is fine, I swapped on the box with another bedroom and it worked fine. I was not in the attic as there was no rain and house is only 3 years old.

I was thinking something similar, all of the outlets work I checked that with a table lamp. Problem starts with switches this would mean I would have to dig in to the drywall to see if there is a problem with where it moves from outlets to switches. Reluctant to do so as I did not do any drilling or make any holes in the drywall.

Any other thoughts? Is there a way to find a spark/short behind a drywall. I will check the attic as well, just have to borrow some tall ladder :) Tnx again for ideas

I would have to dig in to the drywall
Why would you say that? Just check connections of wiring in the last outlet box.

Why would you say that? Just connection of wiring in the last outlet box.

Sorry I thought I mentioned earlier that I checked all connections and they were all solid including outlets and switches. So I figure it has to be somewhere behind the drywall.

Not something that would be in the wiring itself unless something has been done that could have damaged the wiring.. Replace the last outlet.
Before tearing into walls, run a temporary cable outside wall from last outlet to switch.

Replace the last outlet.
Before tearing into walls, run a temporary cable outside wall from last outlet to switch.
That is a great idea. Tnx will post back the results