My 2014 RAM 1500 Tradesman's OEM third brake light (CHMSL) has been inoperable for the past two years. The cargo lamp works fine. I replaced the entire lighting package with a new LED version but the brake light still does not work. The AAA shop did a state inspection and said there was no current found in the brake wire going to the lamp but they did not have the capability to troubleshoot. So I took the vehicle to a local Dodge dealership and had a diagnostic performed whereby they stated I needed to replace the TIPM (the service tech listed it the Body Control Unit or BCM, but parts department employee stated it had to the the TIPM as there was no BCM listed in his parts manual). I replaced the TIPM with new MOPAR part (68192083AH), still the third brake light does not work while the cargo light works fine. I did a hard reset by disconnecting battery, reconnect and then turn key for 12 seconds key to RUN, shut off, then start vehicle, to no avail. This truck has no power windows, door locks or a FAB and from what I understand should not require any "programming" by the dealership.

Does anyone know what the fix might be? I cannot find any mention of this specific problem online that was not corrected by a new TIPM or light package.

 

According to theory, the brake lights do indeed go thru the BCM, which should be on the left side of the dash. (I assume that's underneath somewhere.) Cargo lamp goes thru that as well.