Link is in the OP for ordering OBD Bypass harness.
For your 1500 radio upgrade, at a minimum....
7 speed Conversion harness with Single Zone ATC wiring (temp/humidity sensors) plus BCM config changes with AlfaOBD
18/19 Ram RADIO: 68331631AH (UAQ 4c Nav)
or 68331635AH (UAS 4c)
18 Premium USB Hub (Supports Apple vs stock one, which works for Android only)
PN: 68328704AC (RAM)
or 5XG28DX9AC (Compass)
* 18 HVAC module (vs 13-17)
.... current one will often work with ATC feature/hardware active
* 14-18 ram 1500's have a variable displacement compressor (typ. associated with the 7 speed fan)
>> 14-17's w/RAx = 68268186Ax HVAC module
>> 18/19's w/UAx = 68366552AA HVAC ** module (this one for you)
Most of my long wait times for harnesses at the moment are due to surge of orders from folks who bought 'full' UAQ/UAS kits elsewhere and had problems with the HVAC because they don't have ATC that could have been built into harnesses.
M² Mods.