Question about car 4 speed

Ok I have another question about the 04 dodge stratus lol. I’ve always wondered why the heat fan speed blows out softer than fan speed 3. I haven’t used the a/c because it was wasn’t too cold but now that it’s getting colder, I need the heat and now Im reminded that speed 4 feels like speed 1. So basically if I turn it to speed 1, I‘ll feel a little air then something , the speed 2 blows out harder, the speed 3 blows out even harder, then speed 4 blows out as if I put it back to speed 1. And I’m wondering why?

I’m not too bothered because speed 3 blows hard enough honestly and feels okay but I’m trying to see if it’s problem with air? I would think speed 4 would blow the hardest of all but it’s softer than speed 2 and 3. Or is it supposed to work this way? Anybody that knows about the dodge stratus fan speeds or car fan speeds in general , can maybe explain if this is normal or not?

You are going to need a new fan and with all the other problems with this 15 year old vehicle I think it is time to start looking for a replacement vehicle.

The blower driver for the highest blower speed in the body control module is defective,


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Yeah, I honestly do want to start saving for a newer car haha. maybe a 2017-19 dodge charger. Doesn’t that sound nice?

I’m not totally concerned, because I don’t plan on keeping this car for more 1 year at most and speed 3 is honestly good enough, I feel warm with that setting. But still, what exactly do you men by the blower speed in the body control module? What needs replacing and is it usually very expensive to replace like ($700+)?

Are you sure its blowing at all or are you just feeling air coming out the vent. On older cars you used to get outside air even when the fan was off . If its not running at all and is just outside air coming in then the resistor is probably shot for those speeds and usually those arent too expensive .

It has to be blowing. Because if it was just air from outside then Wouldn’t it be cold and not hot? Since it’s cold outside? I hear and feel some air coming out but it’s just not blowing fast, it feels like the speed is on #1 and not the highest at all.

Chrysler products usually let the pressure of air coming into the heater move the heated air into the cabin at highway speed even without fan assist. That can make the cabin nice and quiet and if you use the fan off setting it prolongs the life of the low speed setting of the resistor.

I had a 2004 PT Cruiser, The turn signal was controlled by a $5 flasher. My Granddaughter had a 2006 and the turn signal was controlled by the Body Control Module $$$. The 2006 also had brake lights controlled by the TIPM $$$$. The high mounted brake lights were controlled by the brake light switch. I may have that reversed but I know they were controlled separately.

This is why I don’t think people will be looking at today’s cars at old car shows in 50 to 70 years. Most of today’s cars except in the rust belt will die with a whimper, not a bang’ because of what used to be minor problems that are now too expensive to troubleshoot and fix.

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Most cars have always died. The few that remain do it because someone has decided they want that particular car. The fact that one has a brake light switch and another has a digital body control module might appeal to someone who likes to mess around repairing things, but my sense is that most car collectors are living out dreams and fantasies.

The original question is interesting, but it makes no practical sense to try and fix this issue. Use speed 3, ignore the speed 4 setting, and hope your '04 Stratus gets you through the next year. I recognize your curiosity, but I can tell you from personal experience that trying to “fix” something like this is way more trouble than it’s worth.

No. Air from outside is passed over the heater (when you have it set to heat) whether the fan is blowing or not. All the fan does is make the air go faster.

When driving on highway once my vehicle has warmed up I turn off the fan, but keep the temp the same. The air flow at about 70 is more then enough to keep. cabin warm. Off highway I may have to turn on the fan.

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Ok. I understand but I’m pretty sure it’s blowing because I can feel air coming out of the vents. When I set the to speed to 0, I don’t feel any air blowing out, so that means speed 4 does make air blow out but not fast like it’s supposed to. i

Yeah me too. I’ve noticed that when I’m going 60-80 mph on the highway the heat gets a lot hotter. And at that point I’ll have to turn it off or switch to a lower speed because that hot air constantly blowing in your face does get irritating lol.

Yeah I agree. And im not getting it fixed because speed 3 is good enough for me. And even if I did want to fix, I would not fix for more than $59 bucks lol.

I was just trying to see if it was supposed to operate that way because I’ve been wondering and never could find a real answer online. And my cousin Said he thinks that it’s supposed to be that way but not sure because he doesn’t know much about my car and he said he never uses speed 4 on his car anyway.

Anything that has 1,2,3,4 is supposed to be different . Why in the world he would think 4 and 1 would be the same is beyond me.

In older cars the fan speed function used different combinations of resistors to produce the different speeds. The electrical power was divided between the fan and the resistors. In that design, fan speed number 1 (lowest speed) usually failed first b/c that was the one that sent most of the power to the resistors. They’d heat up and fail. This is a pretty rudimentary circuit design method to control DC motor speed and wastes a certain amount of electrical power, converting it to heat. Some of the more modern cars use a more sophisticated electrical motor-control design using transistors, and in your case apparently one of the transistors involved w/speed 4 mode has failed. The upside of the transistor method is resistor failure is forestalled. The downside is the transistors can still fail, and replacing them is more expensive than replacing simple resistors.

It’s possible however the problem isn’t a transistor at all. The speed control switch or a connector may have failed.

Well it’s not like we’re mechanics or know much about how the air conditioning works in every car. I’m pretty sure he figured it wasn’t working because at first he said it might be a problem with my motor blower. Then later on he aid maybe I don’t need to fix and it might just be how the car made. I think he only said that cause he didn’t want me to fix it because he thought it wasn’t a big deal cause air was still blowing on other speeds. Even though, as I’ve already said, I’m not trying to get it fixed anyway.