Truck heater not heating

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Probably a blend motor under the dash, I believe they are behind the glove box in that model.

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Was about to post the same thing, I think it will throw a code, but unsure of that.

Costs to get it repaired can vary, as some will say the whole dash needs to come out first. Part is inexpensive.

probably a stuck thermostat, takes about five minutes to change, at least that's how I fixed the heater in my '71 LTD

First check your coolant levels. That's the easiest fix. Then it could be a thermostat, bad heater core or faulty blend door.

All the parts are fairly cheap. Fortunately the dash doesn't need to come out if you need to replace the heater core or blend door. You can access them blend door actuator and heater core by removing the glove box, if someone tells you they need to remove the dash on a 2010 they're gouging you. You do have to drain the coolant if it's the heater core, that can be a pain in the arse if you don't have garage space and time.

After your truck is warmed up, grab your heaters hoses and see if they are getting warm/hot. That way you could at least eliminate if your low on engine coolant reaching your core or if one hose is warm but other is not, might have a stopped up heater core with junk in it. Course of action would be to flush it out. If both hoses are getting hot, next step would be worrying about temp blend actuator behind dash.

You heater hoses are normally the two black rubber hoses going into the firewall/backside of your dash on the pass side of your truck when you open the hood.

Hijack… help me OT mechanics.

2015 jeep wrangler jk. Only when the air temp is below freezing. Driving along and the engine throttle warning light comes on, engine temp gauge goes to zero, radiator fan kinks on to high. There is no visible change in my engine performance. I turn it off and it all resets and I go about my way.

In a 20 minute drive to work it may happen 2 or 3 times. Most of the time it’s after de acceleration but once it happened while cruising in a straight away.

I replaced my engine coolant temp sensor as my research said it was most common issue and did not work. ChatGPT says wiring issue. I’ve visible inspection exposed wiring and connectors finding nothing.

Where do I go from here? Thermostat, throttle body, is there another sensor?

Insert jeep joke here

Edit: my heat is not as warm as it used to be to be in this frigid cold but that may have nothing to do with it. The thread title caught my eye though

As someone else said, most likely the blend motor. Relatively cheap part and easy fix. You will have to remove the radio and AC control console. I recommend removing the glove box, too. A right-angle screw driver will be your friend because the angle is really tight and tricky.

Replaced the one in my son's truck back in the summer.

ETA: they sometimes make a click-click sound when switching between temperature and fan speed settings. That's because the gears are vinyl and when the damper is stuck the skip.

Here you go: Dorman 604-252 HVAC Blend Door Actuator Compatible with Select Ford / Lincoln Models $18

Well I forgot info. I have had a check engine light and the code has been P0128 - engine coolant temp is below thermostat regulating temp. Had this for 3 years now. Couldn’t get it to clear. My engine temp on the dash gauge is always around 190 F where I read that keeps should be in the 200-215 range.

Could the thermostat be stuck open or open further than designed when it does?

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jeep wrangler

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found your problem

Thanks to you and Pirate. I think I’m going to test/swap the thermostat. All of this kinda clicked as I talked it out. It’s running cooler than normal and throws the error in extreme cold. I bet the thermostat spring is bad/weak and when it opens, it fully opens instead of slightly based on sensor readings.

Turning the car off may allow it to close to the proper position based on temp? Basically resetting the condition