Dome light button turns door chime on...please help!!!

Posting this here in hopes I reach the most people with the chances of someone knowing what is going on with my truck! (2004 Tacoma)

Background: I am currently in the middle of project that is adding lights around my truck to a 5 pin relay that uses power from the dome light on the door switch to send a signal to the relay to turn on the lights around the truck (this is to allow for them to act like puddle lights and turn on with the unlocking and door opening of the truck). The 5 pin relay also allows for a rocker switch connection so I can also toggle the switch to turn the lights on.

This system worked as intended until I pulled it out of the garage to clean up my work space. I discovered that when the key was in the ignition, the lights would not turn off.

Trying to trouble shoot this issue, I assumed this was due to the fuses. (Side note: My dome light fuse is supposed to be a 15A, had a 10A installed until it blew, replaced it with a 20A and has been fine, I am aware I am breaking rules using a higher rated fuse). I thought maybe this issue was due to fuse rated too high sending more amperage to the relay keeping the lights on. I swapped it with the 15A fuse on the interior fuse box labeled HORN.HAZ as it seemed like an okay one to pull for this test.


Pictured above is the fuse that I pulled to test this theory out.

What I discovered after this fuse pulling, was that my dome lights no longer would turn on, however, when switched to the on position OR pressing the button for the front map lights, the door chime (the beep that lets you know your key is in your ignition) was on constantly without the keys in the ignition. On top of this, if I pressed the front map lights, it would randomly unlock the doors. Laughed this off thinking it was hilarious my dome lights no longer turned on but rather turned the door chime on.

This was a funny joke until I switched the fuses back, unplugged the battery for about a minute, and still had the same issue of no working dome lights but sounding the door chime when they were pressed.

Additionally, I unplugged the wire I had tapped into the dome light to turn my auxiliary puddle lights on to get everything close to normal as I could.

I genuinely have no idea on how to start trouble shooting this. Did I mess up a fuse box relay that deals with this circuit when I pulled the fuses? Is there a way to reset this? Is this an ECU issue that needs to be reset?

I am desperate and would really love to use my dome lights to illuminate instead of sound the door chime

Any and all help is greatly appreciated. Thank you!

 

It sounds like you may have fried the Body ECU, the Body ECU supplies all the power to the interior lights, it also controls the door locks and warning chime. Power to the Body ECU for the interior lights is provided by the DOME Fuse (15A)
It's not a good idea to draw extra power from a circuit that is supplied by a module, tapping in a relay probably wouldn't hurt but having a short (something blew the fuse) and then putting a larger fuse than specified and having a shorted circuit I suspect may have sent too much current through the module and popped something.

It's never a good idea to install a fuse of a higher current rating than specified, the fuse is there to blow instead of something else if too much current passes through a circuit. Most circuits are designed so under normal conditions the circuit draws a maximum of around half the current of the specified fuse.

Most fused circuits on vehicles anymore are barely capable of handling the current of the specified fuse to begin with, any more and things can start melting or you can let the magic smoke out.

 

This was on another Thread, Respectfully giving the Link: https://youtu.be/FPKN25EpN6s?si=NooXpfVg9Hmg8tIN

This video the ECU thing became fried.