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2001 Dodge Caravan does not blow heat at high speeds

Hello,

I have been having some issued with my Car for some time and have been looking for solutions online. I have a 2001 Dodge Caravan and when it is parked or moving at a low speed below 50kph, the heater works well and I do feel it but when I travel at 70kph and above, the fan still blows but I do not feel the heater working at all.

I have changed the heater resistor under the dashboard by the passenger side but the error still persists…

Could someone please help?

Also, I have checked the coolant level and that seems very okay too.

Have you tried replacing the thermostat?

If the thermostat is stuck open, heat will be stripped from the radiator/heater core at high speeds.

Tester

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Could be your engine compartment fan is spinning all the time, which won’t allow the coolant to reach normal operating temperature. When travelling at higher speeds the airflow through the radiator is already enough, & the radiator fan is supposed to turn off. Is the dashboard coolant temperature gauge showing a normal reading, about midway once the engine warms up? Did this problem start soon after some work was done involving the cooling system?

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The dashboard coolant reading is always on C (cold). What is a quick fix i could try…

cc @George_San_Jose1

The quick fix is as @tester told you… replace the thermostat as this is clearly the problem based on your last post.

4 Likes

If the problem isn’t the thermostat, another idea, pop the hood to see if the radiator fan (engine compartment) is spinning after you first start a cold engine. It shouldn’t spin at idle until the engine warms up. Next is to check if it is spinning (at idle) immediately after you’ve been driving at a 45 mph steady speed for 10 minutes. It shouldn’t be spinning; although be careful b/c it may start spinning while you are looking at it b/c the coolant will warm up quickly as it continues to idle.

I just started the car and the fan wasn’t rolling as we are in the cold of winter here in Canada. Presently, it is -26 deg C. Maybe it runs while on high speed… I dont know … Should I just disconnect the fan and see how it pans out since we are in the very cold of winter?

@Tester if it stationary or at low speed, the heater works. Do you still think I should look at changing the thermostat?

Yes.

Tester

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I doubt the problem is the fan given what you say. That’s pretty cold weather you got there, maybe that’s the problem, the car wasn’t designed for that cold of temperature. What I’d do next if I had that problem is start the engine, the fan won’t be running, then let it idle for 15-20 minutes. That should be enough idling to get the coolant to close normal operating temperature (90 deg C), at which point the radiator fan should start spinning. If it never starts spinning and the dash gauge continues to read below normal operating temperature pretty good chance the problem is the thermostat. If this is the original thermostat, more than “pretty good”. Theremostats lead a tough life and most start to fail around the 10 year mark. Your caravan is what, 18 years old?

At -26 degrees your heater core will simply not keep up with the volume of cold air rushing into and thru the system. Turn your fan speed to the lowest speed setting and I believe you will get warm(er) air. In addition, a backflush might also help raise the temperature.

@kurtwm1 I will try the lower speed tomorrow morning and I will post feedback

I have been driving these vans for years including a 1999. They have always heated well. I live in northern Michigan. The dashboard reading is always cold. Change the thermostat already and drive warm.

I was a northern Ontario kid. Minus 26C is nothing. Caravans can handle the cold just fine. This is definitely a defect, not a design problem.

I grew up only a couple of hours from where a lot of car companies used to do their cold weather testing.

The temp there is -15F. Cars are designed for that and much colder temps. Typical antifreeze mix is good to -34F. Used to be -15F meant more than a few cars didn’t start here in MN and WI unless they were in good condition. Today’s cars don’t have trouble nearly as much as those from the carburetor days.

Get serious .

Hello,

So today, I tried to warm up the vehicle and I noticed that the temp guage on the dashboard rose up but not to the middle, and as such the heater worked… and on driving for like 10 minitues at 70kph, i noticed it had dropped finally… till i finished driving for like 30 minutes, it was blowing cold all through…

SO, as you all have advice, I went to buy another thermostat and i checked on YouTube on how to install it, which I did (without changing the gasket - I got to know about that later), added more coolant, started the vehicle and confirmed that nowhere is leaking (coolant) … was adding more coolant while it was running…

On removing, the old one looked like something like this… dismantled

I will see how it by tomorrow and also give you guys the feedback…

I had to buy a tool set also to achieve this…

And the new one…

Please watch your coolant level very closely and for leakage around thermostat housing. To be completely honest with you, if I had forgotten to use a new gasket when changing a thermostat, I would go back and put one in. Overheating is a sure way to kill an engine, and I wouldn’t want that to happen because of my mistake. And it is a mistake. A used gasket is compromised, and may not leak now, but is suseptible to leaking at anytime.

Yeah… I will watch the coolant level closely. Also maybe during the weekend, I might go back for the gasket.

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