Fan stops working but starts again after hitting the fan controls

[banib]

Hi everyone,

If searched through most of every post there is about the fan/AC issue but to no avail.

Here are the issues I'm having with my 2012 Aygo (Left hand drive):

- When starting the car, no fan at all - not even on the lowest setting

- After testing all the fuses in the car I got frustrated and hit the fan control quite hard and alas - it started working perfectly!

Then after turning of the car and starting it up again the fan stopped working. Again, frustrated I punched the control module and it started working again.
When pressing the A/C-button, the button lights up and I can hear the compressor starting. 

So, the "go to method" to get the fan to work is punching the module quite hard.

Due to it working after being hit I've ruled out the resistor/fuses being the issue.

But I'm unsure if whether or not I should replace the motor or the fan controls in the dash.

Any tips on how to diagnose this?
 

The image shows where I'm hitting the control unit 🙂

 

[Derek.w]

I presume the control is connected to a multi switch or veriable resistor in ither case spray it with Electrical Contact Cleaner I try this first.

Do not use WD40

You need to tug hard to remove the dial that may give you access to screws if so slaken off slightly and spray inside if not remove ashtray to locate any hidden screws to remove lower central coulomb.

[Stecha]

Quote

Due to it working after being hit I've ruled out the resistor/fuses being the issue

Just my 2p worth

IMHO, it could be you're jolting the resistor into working temporarily by jolting it - my suggestion is - replacing it - but obviously I can't guarantee that's the solution, but it does seem like it by what you've said

[flash22]

In all honesty, i would get in the passenger foot well and with the fan turned on give the motor a tap with a screw driver handle, i would also remove the cabin filter and make sure it's clean i have seen 10-15 year old cars with their original filter

 

[Derek.w]

Control may be a veriable resistor if so dirty contact inside switch unit thats why I sugested electrical contact cleaner.

Poor soldering, burnt contact is another possibity.

Vibration affects this type of fault.

[flash22]

It's a switch it sends 12v to 1 of the 3 legs of the resistor (4th speed is direct), the blower resistor is in the duct work to cool it, a bad segment or worn brushes on the motor is more likely a thud or knock just jolts the motor, a bad resistor will give you no speed control 1-3, 4 is direct to ground

The switch is on the ground side

IIRC, the motor is one of those cheap PSA parts made by Valeo