2002 tacoma extended cab 4x4 2.7 dome light not working

Hey community new member here.
I bought a 2002 taco in November and the dome light was working. I did run the battery dead because I left my scanner plugged in.
I've read several posts on this but nothing is exactly what I'm dealing with.
Dome light is not working. Either using the switch to turn it on or opening the doors. The 15 amp fuse for the dome light is good. This also powers the clock and the radio. They all work. Purchased some LED lights thinking it was just a bulb. Still not working. I checked voltage and only get about .6 volts. I unplugged the fuse to verify that was the right circuit. Trying to find theory of operation for the body control module. Thinking that it may have timed out and that's why it's not coming on. I don't know why a module would be used for a dome light. If I can't figure it out I'll just jump power from where power enters the module and out to the dome light. Not going to spend several hundreds of dollars for a new module. I have a wiring diagram just not the theory of how it works.
New update. Still haven't found the issue I will look further into it Monday. If I have the light in the on position it won't come on. If I turn on either courtesy light, the dome lights nice and bright with 12.5 volts dc. When I turn off the courtesy light, the dome light also goes out. Still doesn't work with the door switch position.

 

Wiggle the bulb? Use a test light or volt meter at the bulb’s connection to verify as the switch itself may be bad

 

The theorey is that they run power through the BCM to turn the dome light on/off to prevent draining the battery if the door is not fully closed or the switch is left on, thats the theory and I have never tested. The door switches provide the ground... lots of times just snapping them with your finger forces the contacts to self clean.

.6 volts at the bulb contact using what as a ground point ? Verify that your meter is measuring DC voltage and not AC voltage, dont ask me how I came to this observation.

 

make sure the contact on the back of the switch isn't pitted or corroded and is making good contact, I had a similar issue once upon a time and it was the contact. Just remove the Phillips head screw going through the switch arm to remove, be careful... it has a small spring that applies pressure to the contact.

 

My 99 Dodge after a period of time (maybe 30 minutes) will turn the dome light off if the door is left open.

 

Ok I found it. This is why I asked about the theory on how the body control module works. The problem was the bulb in the dome light when out and I replaced it with an led. The bcm doesn't recognize the bulb because of the high resistance. With the led bulb installed, if I used my test light and touched the positive side, it would light the test light and the led bulb. As soon as I removed it the led would also go out. I took one of the regular bulbs from the courtesy light and put it in the dome light and it works. I guess if you wanted led's then you might have to install a resistor of the same resistance as a regular bulb. Don't know if this would burn up the resistor. Hope this helps someone else who is going through this.

 

Using the ground side of the bulb. Also Using a separate wire from the battery and touching it to ground. If I ran the wire from the positive side of the battery to the positive side of the light. It would light.