2nd Gen Non-Engine/Transmission 2000 3500. no brake lights and ABS moduale

[KKunz]

I have a regular cab 2000 3500 cab and chassis with 6speed, truck was bought new by me in 2000 and I'm the only one who ever works on it so I know the truck pretty well. its bone stock except for a 10' steel flatbed. truck is a my brake lights quit working checked all fuses and replaced the brake switch under the dash. I thought my problem could be my trailer brake controller so I unplugged it. when the truck is sitting key of I have 12volts coming out of the blue wire on my 7 pin trailer connected. I cannot get the blue wire to not have power unless I pull the 40amp fuse under the hood. blinker work fine on the truck and trailer plug but when the headlights are turned on I get two separate pins on my trailer connector that light up but the tail lights work fine. about a year ago my ABS module started making a clicking or buzzing sound even when the key is off. I pulled the ABS fuse under the hood and have been driving it like that. its used mostly on dirt roads pulling a 35' gooseneck and just did not feel like spending the $$$ to fix the ABS module. If the fuse for the ABS is put back in it makes no difference with the tail light brake light issue. can the ABS module affect the tail lights? the wiring is good from the cab back no splices or repaired wires all wiring is factory at the back of the truck where it connects to the trailer plug and tail lights. any suggestion on what else to check? what am I over looking? if any one has a wire schematic of the taillights and where the go inside the cab and under the hood?

 

[Road Dog]

The brake light is also the turn signal light so the brake circuit goes through the multi-function switch (aka turn signal etc) on the steering column. My 2001 FSM shows that the ABS module has nothing to do with the brake light. The multi-function switch does fail.