That is unfortunate
Well if you only moved the wiring going to the rear lamp then as you say maybe something in harness chafed (or still something else wrong with that rear lamp). I know these harness branches could get tangled in the mounting attachment for lamp. So for now I would stay focused on whatever portion of the harness you handled and the rear lamp (which side was it?).
As a test you could completely disable the tail lamp feed to this rear lamp and drive it for a couple days to see if problem goes away which would isolate whether problem is just with the lamp or somewhere else. This would be done by "backing out" the brown wire going into cavity "D" of the rear lamp connector. You would have to put some electrical tape over the terminal to keep it from shorting out when removed.
To remove the wire you would need to temporarily take off the plastic retailer on back of connector which helps retain wires and then depress a tang on the terminal you want to remove from the front in order to back out terminal (need a very small tool to do this). Push the tang on terminal back in place so when you reinstall it snaps back into connector.
The only problem with pulling terminals out of sealed connectors (as well as taking a bulb out your lamp) is that is messing up the sealing of the lamp assembly against water intrusion. So these are things you can only try temporarily.
In regards to the bulb you removed, did it look like a filament was burned open, melted base, heavy corrosion on terminals, or did everything look OK? I think this bulb is a #3057 if you need to get another one
Finally I think you said you were still having problems with headlights and park lights being on during daytime. Since your Service Vehicle Soon light was NOT also on, it somewhat narrows down the problem. Likely it is an issue with Ambient Light Sensor or wiring for sensor have open circuit or short to ground. Take a look at the light sensor
http://www.geocities.com/raj380/mali...bientlight.pdf
There is a potential it might have fallen out of its mounting on defroster duct and is stuck sampling light inside your instrument panel (where it is always dark)
Enough for now
