2024 Lariat - Heat Not Working Well

[MrLoganRoss]

I was running FDRS today for the only updates available to me (ACM and PSCM). When I logged in, I noticed there had been a previous DTC indicating an issue with the blower motor.
It is not a current DTC and the heat seems to be a little better. I will keep testing over the next week since the temp is in the upper 30s and 40s. Maybe it is an issue that worked itself out!

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[StevenC56]

It doesn't get extremely cold here is Central California, but it has been dipping down into the 30's and my windows are quite foggers up when i get in my truck. Putting the defroster on "Max" clears the windshield and side windows in just a few minutes and heats up the cab quite nicely at the same time. You can definitely hear and feel the heat pump humming through the truck when this is going on.

 

[invertedspear]

I figured remote start was "Full Accessory", but it must be more because it energizes the HVB relays which you need to get the heat. Today I noticed that when the Lightning is plugged into the charger and I remote start it, it actually warms up nicely. The previous few remote starts were when it wasn't plugged in. Not sure why this seems to make a difference.

There isn’t really such thing as “remote start” for the lightning. At least it doesn’t act like how I would expect a remote start to if it were just copying its ICE siblings. You can remotely start the climate control but after you get in, you then still have to “start” the truck, screens and radio aren’t on when you do this. If someone gets in to the passenger seat and hit’s the start button the truck switches from “remote climate control started” mode to “full accessory mode” which turns off the climate control except for the blower fan for some reason, but turns on the screens and radio. The climate control won’t come back on till you hit the start button with your foot on the brake.

 

[davehu]

I didn't read all of these posts but while perusing the forum I found a post from a guy in Alaska who has a '22 Lariat and a Mach E. His experience is that the Lariat heater will make it comfortable even at negative 40 degrees! I'm in Arkansas and we get to the teens and my heater has worked fine. your's needs to be looked at

Post #9 from Software Controlled Range

 

[MrLoganRoss]

I was running FDRS today for the only updates available to me (ACM and PSCM). When I logged in, I noticed there had been a previous DTC indicating an issue with the blower motor.
It is not a current DTC and the heat seems to be a little better. I will keep testing over the next week since the temp is in the upper 30s and 40s. Maybe it is an issue that worked itself out!

OP here again. Another cold morning and no issues today. I am really hoping it was just a module issue that needed to work itself out. If it continues to be good, I will update the title of this thread to reflect “Solved”.

 

[Webbo85]

Confirmed this weekend that my heat is working the same way it has for the past 2 winters. It was around 10F outside up the mountains, got in the truck and started it. Set the heat to 78 and Auto High. No air came out at all until the air got to temp (less than 2 minutes), then it came pumping out the Windshield vent and the floor vent, never out the front. When the truck heated up inside, you could hear the fan speed decrease. Now if you change the temp down to LO to kick on the AC, it's blasts you in the face with cold air. This is how the owner manual describes it as working correctly. And my wife's Mach-e works the exact same way. Both the vehicles get warm rather quickly in my opinion. If yours isn't working that way, something seems off. I did notice that the HVAC works better at extremes, so set it to HI or LO initially to get it going.

 

[MrLoganRoss]

Update: I have a ford appointment soon, but I think I have figured out that is is mechanical. Either blower or flap to direct air. If the heat is on Driver Focused, I get cold. If the heat is not on Driver- Focused, the cabin warms slowly, but I only feel/hear the air from the passenger side.

 

[Webbo85]

Curious to hear what they find. Good luck!

 

[MrLoganRoss]

The problem persists. And it is intermittent. I dropped it off at the dealer yesterday, and the first response from the first tech was a bit of a flip off. Simply telling me they turned it on and it blew warm air (yet the service advisor had experienced the cold air when I dropped it off after it had been driven). Therefore, I should just deal with it because“these cars have tiny space heaters“. I find that absolutely unacceptable. The service advisor is very nice and he is working with the foreman to try and resolve the problem. I reminded them that there has already been a DTC for the blower motor. My hope is that they will look at that next. I have faith in the dealership that they will do the right thing.

Based on my research, this is not wholly uncommon. Below is a list of things that I have identified as being issues for other people with lightnings. For those of you that have had Problems, which was it for you?

(1) coolant issue (flush may solve unless there is a leak);
(2) heater blower motor or blower motor resistor (remember the DTC);
(3) thermostat/temperature sensor;
(4) temperature blend door actuator;
(5) cabin coolant heater module joint solder (this was a '23 recall);
(6) engine coolant control valve.

 

[TaxmanHog]

Below is a list of things that I have identified as being issues for other people with lightnings. For those of you that have had Problems, which was it for you?

(1) coolant issue (flush may solve unless there is a leak);
(2) heater blower motor or blower motor resistor (remember the DTC);
(3) thermostat/temperature sensor;
(4) temperature blend door actuator;
(5) cabin coolant heater module joint solder (this was a '23 recall);
(6) engine coolant control valve.

Remember that 22/23 systems are different than your 24.

I've not seen a schematic of this new system but suspect the items struck out are not a factor on your truck.

I'd think that the HVAC module under the dash only has condenser/evaporator coil to transmit cold in hot season or heat in cold season.

The glycol heater core might no longer be in the system, diverter valves may have been reconfigured to deal with battery thermal management and eliminated sub-loops for the HVAC system.

Issue still in play, blower motor function, logic controlling the blower motor, sensors not picking up conditions properly, fresh air blend door actuation and logic.

New issues for '24 truck might involve the vapor heat pump system, refrigerant charge, reverser valve, control logic.

Does the system blow hard if you use MAX defrost, high fan speed & heat??

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