Intermittent electric-hell Issues 2003 Sequoia 4WD SR5

The truck runs great after some work as it sat for a few years due to the electrical issues.
The symptoms seemed to progressively add-up;
Doors lock then unlock when closed, rear hatch electricals don't work, drivers door controls only work on that door (all others work on their respective doors), courtesy lights on doors out, the "key left in ignition chime" doesn't ding, and there's an intermittent parasitic drain.
I've replaced the back-door ECU, driver door ECU, and the Body ECU. Nothing. Pulled fuses and tried to isolate the drain. Nothing. Tested all relays I could access.
There's some light rust under the dash by the instrument panel fuse/junction box; removed the box hoping to find a mess in the fuse box but no corrosion or obvious issue there.
A Clue! When I would pull the 7.5A fuse to the body ECU and then put it back, the problems would stop for a variable amount of time; maybe 40 seconds, 10 minutes, or ???
Then I drove it without the fuse in. Windows worked but were "jerky" going up and down while driving. Got home and put fuse back in. After that, pulling the fuse no longer solved the issue at all.
But, when pulling out the fuse box a few days later, I broke the 40A AM1 fuse while removing it. When I replaced it, no issues again for about 5 hours!
I thought something I did in that process solved the issue. Nope. Same issues this morning.
Does the fuse-pulling-everything's-okay-for-while-thing indicate anything?
I'm losing my mind over this. Help!
*I don't know if the back door (hatch) works like the other doors regarding sensing if it's open or closed. I can't remember if it activated the interior lights (it doesn't currently) when opened.
**There was an aftermarket DVD player installed at the dealer which I removed because I thought it was the source of the battery drain. Wiring seems fine.
***I modified the front dome lights to fade out like the back ones do but the issues were occurring prior to that.

 

Did you find any evidence of mice in the vehicle?

 

No mice. It seems like there's an issue in the front passenger door wiring that's causing it but I can't find the exact issue. I can make the issues start/stop when wiggling the door wiring harness. It's crazy.

 

We had a similar issue with my 1993 FZJ80 Land Cruiser, the door locks would go crazy at times, interior lights and windows wouldn't work and cause it not to start. It turned out to be a corroded circuit board in the driver's side front door. It took forever to track it down, water had gotten in from the outer sill over the years and caused the corrosion that would cause an intermittent short. Found it after getting pissed and slamming the door and heard something rattling around turned out the diodes or flex capacitors or whatever fell off and were in the bottom of the door.

 

Yeah, water inside the door is definitely a thing. Now I need to take the door apart again and look for the flux capacitor laying in the bottom.

 

I decided to tackle my Dart's parasitic draw this past weekend, so good timing on your post.

How much current do you have for the parisitic? My drain of ~40-50mA matched the current required for a surface mount PCB relay on the BCM to trigger, which makes sense since I traced it down to the BCM itself and not any particular sub-circuit. Relays will act strangely when they're going and yours are 21 years old (assuming the replacement was used). Pulling the fuse tied to the bad relay may temporarily fix it if it settles correctly and doesn't have an internal short, so that'd be my guess why you had some intermittent luck.

The other thought would be to check for corrosion at the BCM connectors and other modules.

 

I got a new scanner and finally got the passenger door controls to act up and throw a code: B1215 Door System Communication Bus (GND Short). Once I went through the diagnostics in the repair manual it confirmed a bad Front Passenger Door ECU. This system is connected to all the problems in the back and driver's door. Hopefully, the GND Short in the code was what was draining the power. I just ordered a new control on Ebay. Fingers crossed.

 

Other updates: Everything is working fine electrically since the passenger door ECU was replaced. Jinx! I'd also had intermittent VSC Trac, VSC OFF dash light issues forever. Finally pulled codes from them and it said Translator ECU and two ABS sensor issues. I did some research and there was a Service Bulletin about an issue with some 2003s that had bad programming in the Translator. The fix was to replace the unit with a new one. The part number of the old ones ended in 10 and new ones ended in 11. I've replaced that out of an '04 and so far it's been good. But, it has always been an intermittent issue so we'll see.