When the heater in my 2011 Ram 1500 started blowing cold air, the usual suspects were low coolant or a thermostat stuck open. Both are fixes you can do yourself with basic tools, and I filmed the whole thing so you can follow along.
Signs it is the thermostat or coolant
- Heater blows lukewarm or cold, even after a long drive
- Temperature gauge stays low or climbs slower than normal
- Coolant reservoir is below the line
What you need
- Engine thermostat (fits 2003-2018 Ram 1500/2500 and many Dodge/Jeep)
- Mopar orange coolant (what Ram calls for) or Valvoline multi-vehicle coolant
- A socket set. Mine: Amazon Basics 201-piece mechanic’s set
- A drain pan, gloves, rags and a funnel
The steps
- Work only on a cold engine. Never open a hot cooling system.
- Check the coolant level first. If it is low, top it off and see if the heat comes back.
- If the level is fine, find the thermostat housing where the upper radiator hose meets the engine (the second video shows how to find it).
- Drain some coolant into the pan so the level drops below the housing.
- Remove the housing bolts, pull the old thermostat and clean the mating surfaces.
- Install the new thermostat facing the right way, with a new gasket or O-ring, and snug the bolts evenly.
- Refill with coolant, run the engine with the heat on high to bleed out air, and top off once it cools.
Always check your owner’s manual for the right coolant type and capacity for your vehicle, and recycle old coolant at an auto parts store. It is toxic to pets.
Keep it simple
Small jobs like this save money and build a lot of confidence. For more easy wins, check the Daily Healthy Habit, read how I change my oil, or browse the gear I actually use.
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