Heater fan working intermittently

[elizevdw]

I have a 2013 C Max SE and I noticed recently that the heater fan won't come on. Initailly it would work if I switched the climate control off and back on, but this morning nothing worked. This evening it eventually turned on after driving for about 2o min. It has been very cold - 2-27F? 

[raadsel]

I have a 2013 C Max SE and I noticed recently that the heater fan won't come on. Initailly it would work if I switched the climate control off and back on, but this morning nothing worked. This evening it eventually turned on after driving for about 2o min. It has been very cold - 2-27F? 

 

Just to be clear, you are complaining the heater fan never turns on? Not that it doesn't turn on when you start your car, or for 5-10 minutes after? I ask, just as a reminder, that their is a thermostat that prevents the fan from turning on until there is enough head in the engine, so it isn't just blowing cold air. 

 

Assuming it isn't turning on at all, I could see this being an issue with the thermostat.

[cr08]

Put the coolant temp up on screen and monitor it next time. Depending on the temp called for and outside temp, it'll normally start putting out heat when it is a hair above the cold mark. At least on my Energi. I'm assuming the coolant temp thresholds are the same in the hybrid. Auto climate systems are designed to work this way. No use blowing cold air when the coolant is still cold. The only difference is defrost as it will blow cool air just to have any air blowing across the windshield for defogging purposes.

[elizevdw]

Initially it would turn on, then stop working. The next day it wouldn't turn on at all -even when I put it on defrost. However, today it was warmer (24F) and it worked immediately as I switched the car on. It might be a combination of the cold as well as the thermostat.

[plus 3 golfer]

Initially it would turn on, then stop working. The next day it wouldn't turn on at all -even when I put it on defrost. However, today it was warmer (24F) and it worked immediately as I switched the car on. It might be a combination of the cold as well as the thermostat.

USE ETM to monitor coolant temperature as you will see a digital readout of temperature in ETM rather than the gauge in my view.  Scroll through the screens to find coolant temperature.  You can also start the car (ready to drive mode) with the ETM display up while you drive and note at what temperature the fan comes on.

Edited December 13, 2017 by Plus 3 Golfer

[elizevdw]

Thank you I will give it a try 

[plus 3 golfer]

Also, post any DTC that are on the DTC screen in ETM.

[plus 3 golfer]

Also, are you the orginal owner?  If no, is this the first winter you are driving the car?  If yes, there were software updates (13B07) that enhanced engine warmup time and FE and thus how quickly the coolant would warm up.   If no, I assume you didn't have the problem in previous winters.  Do you know if 13B07 was done as it expired in 2014? 

 

I never drove my car in cold weather prior to having 13B07 done in the summer of 2013 so I don't know how the HVAC performed prior to 13B07 in the winter.

[elizevdw]

Thank you for all the information. I couldn't manage to get the ETM to pop up as suggested, but since I posted this, it has come on straight away but only blowing as a defrost, then not blowing at all etc. It looks like it might just be a bad motor that needs to be replaced. Thank you

[plus 3 golfer]

Thank you for all the information. I couldn't manage to get the ETM to pop up as suggested, but since I posted this, it has come on straight away but only blowing as a defrost, then not blowing at all etc. It looks like it might just be a bad motor that needs to be replaced. Thank you

Are you sure ETM wasn't up as it will be "hidden" behind other screens.  When ETM comes up you should see only the letters ET in the upper left ( the rest of the ETM is behind other screens.  To clear the front screens, one needs to push the OK button. 

 

Also, if ETM was really not coming up, then you may have an issue with the IPC or other module and the HVAC blower motor working intermittently is symptom of the issue not the cause.  I don't recall any reports of the blower motor failing.

[elizevdw]

So, since my last post, I finally got the ETM to show, but by that time the blower wouldn't come on at all - 40 mile trip. For a while I could make it work by switching everything off and then on again. This only lasted a bit. In the last couple of weeks it would only come on if I stopped, switched the car off and then start it again. This happened whether it was cold or not. I had the transistor replaced, but this didn't solve the problem.