Fan Blower Not Working

[mirage-2014]

2014 Mirage:
over the past 6 months, the fan blower has not been coming on at random times when i start the car. car will turn on, but the fan blower will not come on. after several minutes of driving the car, the fan blower will suddenly pop on and work fine (ac and all). there is no rhyme or reason as to when it does not come on. engine could be hot or cold...
lately it has been happening more often. today it hasn't come on at all after 2 hours of driving.
two dealers have looked at this issue. i took it to the first dealer one day when it was not coming on. they said i need a new fan motor. i agreed and when i left the dealer, of course the fan came on while i was driving away. as i said, when it comes on, it works fine. so we didn't put a new fan motor in and i took it to another mitsubishi dealer.
it has been to this second dealer twice. first time- they stated the "terminals were spread out and loose", which they fixed. however, the problem continued later on. i took it back and this time they replaced the blower motor relay. again, the problem persisted later on.

the fan motor was already replaced about a year ago under warranty because of another issue (the fan was making a clicking sound) which fixed the clicking sound and all was fine.
also, i have noticed the fan speed fluctuate randomly while driving. even when cruising at a constant speed or idling, the fan speed will increase and decrease sometimes.

so now my car is out of warranty. i am paying for these "diagnostic fixes" out of pocket.
the second dealer who has corrected the terminals and replaced the blower motor relay is scheduled to look at it again monday. he has stated they are "stumped" and do not know what else to try. they do not believe it is the fan motor because:
1. i have already had it replaced and
2. when the blower does come on, it works fine.

does anyone have any ideas as to what may be the cause? is there a piece of equipment that controls the fan motor speed which may be causing this? has anyone else experienced this?

sorry for the long post, but i want to be thorough. i appreciate any help or input on the matter.

thank you.

[Eggman]

Auto climate control refers to the interior temperature sensor to determine fan speed, heat and AC. I wonder if that is reporting funny readings? The sensor should be very reliable. If it is a problem with the sensor, I would suspect a intermittent connection over a failing thermistor.

Just a guess.

[mirage-2014]

thank you for your reply.

"Auto climate control refers to the interior temperature sensor to determine fan speed, heat and AC."
- 90% of the time i do not use the auto climate feature. i rarely press the auto button.
when i do press the auto climate button, it does react correctly. i will press auto, set the temp, and the blower will adjust the temperature accordingly.

"I would suspect a intermittent connection over a failing thermistor."
- this was my first guess as well. however, i am not very car savvy. what would cause an intermittent connection? a loose fuse? a loose fuse is what i thought, but i cannot find the correspond fuse to the fan motor. do you know which fuse it would be? i have checked them all and none seemed to be loose.

as stated above, the dealer replaced the blower motor relay. is the blower motor relay the same thing as the blower motor fuse?
thanks again!

[mirage-2014]

i should also note, the fan blower NEVER turns off when the car is running once it comes on. not until the car is turned off and and on again will i have this issue.

[Eggman]

And by the way, welcome to the forum. Sorry for the late reply.

I should preface my post by letting you know I'm no mechanic, just an enthusiast of these little cars. We have some Mitsubishi employees as forum members, as well as some auto mechanics, so hopefully they can read this and chime in.

Also, for some reason I wasn't sure that you were describing the blower fan for the passenger compartment or the engine coolant. Since you mention the fan speed fluctuating, I ruled out the radiator fan since I understand it is not a variable-speed device.

Let's see - you said the blower motor and relay have been replaced, which are logical first steps. That's why I focus on the device that controls the blower, which is a little computer of it's own from what I understand. Did your problems start with the new blower?

Not all versions of these cars have the automatic climate control, but I believe your model year North American market Mirage does, so that was a guess on my part. How you use it is important to know. You say that the fan speed fluctuates only while using manual mode, correct? But in auto it never malfunctions? Why not just use Auto? If you don't want the AC compressor running all the time, that function can be easily turned off. Also that could indicate that the problem is not with the blower or relay. If I can suggest something, it would be to at least try to duplicate the symptoms in Auto mode just to see how it goes.

Sorry for raising so many questions. As an owner, I may be unable to help much but am very curious to know the potential problems that may come our way so we can all keep our cars running smoothly.

I'll have to look at my copy of the service manual I downloaded and see what that says about this blower motor. Do you have a copy?

[Eggman]

Here is what I found in the service manual:

---

Group 55B: AUTOMATIC AIR CONDITIONING

---

INSPECTION PROCEDURE 3: The blower does not work

---

COMMENTS ON TROUBLE SYMPTOM
If the blower motor does not operate, the blower motor circuit system may be defective.

PROBABLE CAUSES
•Malfunction of the blower motor
•Malfunction of the power transistor
•Malfunction of the auto A/C controller assembly (A/C-ECU).
•Damaged wiring harness or connectors

---

INSPECTION PROCEDURE 4: The blower air volume cannot be changed

---

COMMENTS ON TROUBLE SYMPTOM
If air volume cannot be adjusted by using the blower control, the A/C control panel, the auto A/C controller assembly (A/C-ECU) or the power transistor may be faulty.

PROBABLE CAUSES
•Malfunction of the A/C control panel
•Malfunction of the power transistor
•Damaged wiring harness or connectors
•Malfunction of the auto A/C controller assembly (A/C-ECU)

Intermittent troubles are very difficult to diagnose. It sounds like your dealer has taken appropriate steps, but I would ask for results of the ECU tests to make sure they actually did the test. The auto climate control communicates with other controllers for data such as engine temp.

I would recommend running in auto mode just to see if the symptoms are present. If the speed continues to fluctuate, I would look at the power transistor.

Best wishes. Let us know how this goes.

Now I ask that you make a garage entry in your account here on the forum, and tell us a bit more about yourself and your Mirage! Don't forget some photos and fuel log. Again, welcome!

[mirage-2014]

so now the fan does not come on at all. can someone please tell me which fuse i can chrck before taking it to the dealer again? which guide conyrols the fan blower? the manual does not state... thank you.

[3dplane]

The fuse is going to be the least likely item to be intermittent.

When the fan does not come on at all is the best time to diagnose.

Turn the ignition to run or start the car. Turn the blower on high.

Go in from the passenger front door locate the blower motor under the glove box (no panels to remove)
and smack it either with hand or some object like the handle of a screwdriver.

If it came on, it needs a blower motor.

If it did not come on wiggle the connector going to it.(white with two wires).
If it came on it could still be the blower motor (internal connections) or like your dealer suspected back then, poor connections
at the connector,so terminal tension could be drag tested etc.

If it did not come on and you do not own a test light,take it to the dealer.

Even if you find the fuse blown,it blew because there is a problem in the circuit and again that could be the blower motor pulling
too many amps due to a bunch of different reasons, a short somewhere else etc. So if you replace the fuse without hunting the root cause down and make appropriate repairs,it just going to blow again.

[Eggman]

The 2014 Owner's manual page 7-38 lists fuses. The closest I can find is one labeled 'Heater' at position 23. I haven't been able to find one labeled 'fan'.

Have you checked that all your fuses are fully seated? Easy check to make, and it's free.

Also, I was able to download a copy of the 2014 Owner's manual, and it was very easy to search for the term 'fuse'. Do you have a copy of this manual?

[mirage-2014]

The fuse is going to be the least likely item to be intermittent.

When the fan does not come on at all is the best time to diagnose.

Turn the ignition to run or start the car. Turn the blower on high.

Go in from the passenger front door locate the blower motor under the glove box (no panels to remove)
and smack it either with hand or some object like the handle of a screwdriver.

If it came on, it needs a blower motor.

If it did not come on wiggle the connector going to it.(white with two wires).
If it came on it could still be the blower motor (internal connections) or like your dealer suspected back then, poor connections
at the connector,so terminal tension could be drag tested etc.

If it did not come on and you do not own a test light,take it to the dealer.

Even if you find the fuse blown,it blew because there is a problem in the circuit and again that could be the blower motor pulling
too many amps due to a bunch of different reasons, a short somewhere else etc. So if you replace the fuse without hunting the root cause down and make appropriate repairs,it just going to blow again.

i did as you said. i smacked it and wiggled the wires. nothing...
then i stuck my hand down in the fan blower motor and gave it a spin, AND IT CAME ON!
so i guess now if i want to have the blower come on, i have to manually give the motor a spin by hand to get it going.
by the way, i have taken it to 3 dealers now regarding this problem. after 375$ in total "diagnostic fees", none of them are helpful. one dealer wants to replace the entire "HVAC SYSTEM" for 875$, another wants to replace the fan motor blower for 395$, and another dealer does not know what else to check after replacing the relay.
i can live with spinning the fan motor by hand to get it started. hopefully that continues to work...
thanks.