Dome light causing electrical dramas?

Is it possible for my dome light to be shorting out and causing other systems to have power with the key off?

This is what I'm dealing with - a few weeks ago I loaned the truck to a co-worker who accidentally left my led light bar switched on and drained the battery. I've only had the truck a couple months and the previous owner put a new battery in before I picked it up so possibly this issue goes back further than that. Since then however the truck would randomly die whether it was parked more than a few hours, to the point where I was disconnecting the battery every night and each day at work to keep it from discharging (yesterday I broke down and bought a battery charger/maintainer) Also, whatever was going on with it, my power windows would work with the key off even after opening the door and waiting 30 second or whatever, the key fob would not work, the heater fan would keep running after turning the keys off but if turned off with the switch would not turn back on until the keys were on again and the passenger airbag light would stay on or flicker like this:
Anyway, tonight I was waiting for my kid and I turned the dome light on (I've had it turned off, not even on door since the first time the battery died by itself) well the airbag light goes out, my windows lose power as soon as I open the door (like they should) and my key fob works again. I'm at a loss. I'd like to think it was just the dome light switch but I'm afraid to leave it overnight in case it drains again. Has anybody else experienced a similar issue? (Has anybody managed to read this far?) A different guy at work reckons the ignition switch might be faulty and I've ordered a new one but tonight's experience makes me think that might not be it.

 

Sounds like a relay is faulty

 

Sounds like... something... with one of the door switches. I'm not entirely sure what, but all that stuff adds up to sound like the retained accessory power wasn't shutting down like it should've when the door is opened.

Also... gonna go out on a limb here and say your battery dying issue was caused by, ya know, all that crap being left on by your electrical system.

 

First do you have a stock Dome Light or an LED?

If LED rip that shit out and get a regular lamp. Start there and see what happens.

The Dome light is controlled by the Body ECU which also controls the Door Switches etc...

This is the circuit for the Dome Light and interior light.

https://www.customtacos.com/tech.ol...toyewd/06toypdf/ewd/2006/tacoma/h/em01d13.pdf

 

Yeah I thought that at first which is why I turned off the dome light, but the door open light has never lit up on the dash.

Also, no shit Sherlock. Lol

Stock dome light. As far as I know the only LEDs on the truck are the reverse lights and the light bar (which I have disconnected for now).

Thanks for the wiring diagram. Hoping I didn't fry the body ECU jumping the battery the first time it died - I forgot about hooking the negative lead to the motor instead of the battery and I realised late I also had a dodgy ground cable from the battery to the body. That is now fixed, hopefully I haven't damaged the ECU and I can find whatever else is going on.

 

Update , just went out to the truck and it wouldn't unlock with the key fob again. Jumped in and sure enough, airbag light is on. So not the dome light switch itself but something connected? Unless that was just a coincidence. Either way, back to square one.
Another clue, heater fan will stay running if on but won't turn on with keys off. Recirc button however lights up if pressed with keys off and can hear door cycle. Another thread talked about fan motor, maybe I should check that out.

 

You need a good auto electrician or and Exorcist.

You have some weird shit going on and it's probably going to be a real pain in the ass to find.

NOTE: It could be real expensive throwing money and parts at it. A good troubleshooter is what you need here.

 

I second that. The blower motor & recirc thing have me rethinking the door switch being bad idea, since I'm pretty sure neither of those are involved with retained accessory power. Which leaves me thinking either ignition switch or magic black box... but it's obviously not just a straight up ignition switch failure since the blower stays on but won't turn back on once turned off.

 

I'm back to ignition. There's a spot on the ignition switch past "Acc" but before "On" where that airbag light comes on properly, not just dim and flickering like it is with the keys off. Just went and tried it now and the blower motor will turn on at that point too. Something must be loose inside the switch and making contact where it's not supposed to. Not sure why the blower motor stays on but won't turn back on when the keys are off but since I've already ordered a new ignition switch, may as well try replacing it before I go any further.

 

Funny story, I did actually ask the dealer to look at it while the truck was in for an unrelated issue...
Me: something is draining my battery, can you take a look?
...8 hrs later...
Dealer: yeah your battery is flat so we couldn't do any electrical diagnostics.

 

Holy crap, I can't wait for my new ignition switch to show up so I can see if that fixes this riddle. Turned the truck off with the wipers going - wipers stop mid wipe, truck turns off normally. Wipers on but not wiping, electrical gremlin stays.

Edit: apparently not, battery is dead. I guess the wipers diverted enough power that everything else behaved normally (power locks work, windows didn't once door opened) but something was still draining it.