For your electrical gremlins, open the engine fuse box and GENTLY seat all fuses, relays etc. You will likely find about half that are not fully seated properly. This alone often solves a LOT of gremlins.
Heated/cooled seats and AC/Heater on many of the Rams only comes on with remote start when the interior is within a certain temperature range. Not sure what years and how many models this is true for but I have seen it on a couple of my buddies pickups.
I would remote start it, and then adjust the temperature settings to max AC etc. Someone may have set it to off during a remote start sycle and that it will retain until you change it.
This is from the owner's manual for my 2021 2500.
Remote Start is used to defrost windows in cold
weather, and to reach a comfortable climate in
all ambient conditions before the driver enters
the vehicle.
NOTE:
Obstructions between the vehicle and the key
fob may reduce this range Ú page 490.
HOW TO USE REMOTE START
Push and release the Remote Start button on
the key fob twice within five seconds. The
vehicle doors will lock, the parking lights will
flash, and the horn will chirp twice (if
programmed). Then, the engine will start, and
the vehicle will remain in the Remote Start
mode for a 15 minute cycle.
Pushing the Remote Start button a third time
shuts the engine off.
To drive the vehicle, push the unlock button,
insert the key into the ignition, and turn to the
ON/RUN position.
NOTE:
With Remote Start, the engine will only run
for 15 minutes.
Remote Start can only be used twice.
If an engine fault is present or fuel level is
low, the vehicle will start and then shut down
in 10 seconds.
The parking lights will turn on and remain on
during Remote Start mode.
For security, power window and power
sunroof operation (if equipped) are disabled
when the vehicle is in the Remote Start
mode.
The ignition must be placed in the ON/RUN
position before the Remote Start sequence
can be repeated for a third cycle.
If your power door locks were unlocked,
Remote Start will automatically lock the
doors.
All of the following conditions must be met
before the engine will remote start:
Gear selector in PARK
Doors closed
Hood closed
Hazard switch off
Brake switch inactive (brake pedal not
pushed)
Battery at an acceptable charge level
PANIC button not pushed
Fuel meets minimum requirement
System not disabled from previous remote
start event
Vehicle Security system not active
Malfunction Indicator Light is not illuminated
WARNING!
Do not start or run an engine in a closed
garage or confined area. Exhaust gas
contains Carbon Monoxide (CO) which is
odorless and colorless. Carbon Monoxide is
poisonous and can cause serious injury or
death when inhaled.
Keep key fobs away from children. Operation
of the Remote Start system, windows,
door locks or other controls could cause
serious injury or death.
REMOTE START FRONT DEFROST
ACTIVATION — IF EQUIPPED
When Remote Start is active, and the outside
ambient temperature is 40°F (4.5°C) or below,
the system will automatically activate front
defrost for 15 minutes or less. The time is
dependent on the ambient temperature. Once
the timer expires, the system will automatically
adjust the settings depending on ambient
conditions. See “Remote Start Comfort Systems
— If Equipped” in the next section for detailed
operation.
REMOTE START COMFORT SYSTEMS —
IF EQUIPPED
When Remote Start is activated, the front and
rear defrost will automatically turn on in cold
weather. The heated steering wheel and driver
heated seat feature will turn on if programmed
in the comfort menu screen within Uconnect
Settings Ú page 258. In warm weather, the
driver vented seat feature will automatically
turn on when Remote Start is activated, if
programmed in the comfort menu screen. The
vehicle will adjust the climate control settings
depending on the outside ambient
temperature.
Automatic Temperature Control (ATC) — If
Equipped
The climate controls automatically adjust to an
optimal temperature and mode, dependent on
the outside ambient temperature. When the
ignition is placed in the ON/RUN position, the
climate controls will resume their previous
settings.
Manual Temperature Control (MTC) — If
Equipped
In ambient temperatures of 40°F (4.5°C) or
below, the climate settings will default to
maximum heat, with fresh air entering the
cabin. If the front defrost timer expires, the
vehicle will enter Mix Mode.
In ambient temperatures from 40°F (4.5°C)
to 78°F (26°C), the climate settings will be
based on the last settings selected by the
driver.
In ambient temperatures of 78°F (26°C) or
above, the climate settings will default to
MAX A/C, Bi-Level mode, with Recirculation
on.
For more information on ATC, MTC, and climate
control settings, see Ú page 59.
NOTE:
These features will stay on through the duration
of Remote Start, or until the ignition is placed in
the ON/RUN position. The climate control
settings will change, and exit the automatic
defaults, if manually adjusted by the driver
while the vehicle is in Remote Start mode. This
includes turning the climate controls off using
the OFF button.
REMOTE START ABORT MESSAGE
The following messages will display in the
instrument cluster display if the vehicle fails to
remote start, or exits Remote Start prematurely:
Remote Start Cancelled — Door Open
Remote Start Cancelled — Hood Open
Remote Start Cancelled — Fuel Low
Remote Start Cancelled — Time Expired
Remote Start Disabled — Start Vehicle to
Reset
The message will stay active until the ignition is
placed in the ON/RUN position.