Technical Problem with cooler-heater fan

[fisakis]

Hi all and I 'm happy I found this team!

I have Fiat Bravo 1.2 16V mod2001 with auto clima air condition and I have this problem:

The fan of the air condition or (if you like) heater fun doesn't work corect always and works as it likes. The switch has the following options: "0"-"auto"-"1"-"2"-"3"-"4". Sometimes, when it is at the option "0", the fan works as it is at "auto" position. After, returning to "0" and then to "auto" again, and so on. This occurs primarily with vibrations by the driving of car or when I throw cuff close to the switch. Also happening in any position and I have the switch, for instance when the switch is in position "2", the operation of the fan would be like turning the switch to position "2" and "3" and again in position "2" and "3", and so on. The operation of the fan, alternate in a position upward and then returns in the position switch, without I change the switch position.

I have changed two times the switch but do it again.

Do you know what it happens? This problem exists from the second year I have the car(2003)

My Bravo is like this (the fan switch):

 

[varesecrazy]

Hi all and I 'm happy I found this team!

I have Fiat Bravo 1.2 16V mod2001 with auto clima air condition and I have this problem:

The fan of the air condition or (if you like) heater fun doesn't work corect always and works as it likes. The switch has the following options: "0"-"auto"-"1"-"2"-"3"-"4". Sometimes, when it is at the option "0", the fan works as it is at "auto" position. After, returning to "0" and then to "auto" again, and so on. This occurs primarily with vibrations by the driving of car or when I throw cuff close to the switch. Also happening in any position and I have the switch, for instance when the switch is in position "2", the operation of the fan would be like turning the switch to position "2" and "3" and again in position "2" and "3", and so on. The operation of the fan, alternate in a position upward and then returns in the position switch, without I change the switch position.

I have changed two times the switch but do it again.

Do you know what it happens? This problem exists from the second year I have the car(2003)

My Bravo is like this (the fan switch):

Hi, and welcome ,

my marea also does this, 2002 and TIRED..

( my 3 year old - 1999 JTD was perfect..)

there are other threads relating to this.. I believe I read it's an EARTH / GROUND issue..,
https://www.fiatforum.com/marea/332122-heater-blower-speed-switch.html

Charlie

 

[Neverth]

Yep, the speed dial just sends analog voltage to the aircon ecu.

Thats the reason why ground reference between the switch and aircon unit needs to be good.
I think the other uses same ground as cig lighter (left side chassis earth), where the aircon ecu uses right side chassis ground. They are connected together, but the wires are not that thick.

If you put something taking several amps to the cig lighter and the fan is acting up, it is most likely the grounds.

 

[varesecrazy]

cheers chaps

just the info I couldn't find..,
now my marea is legal for another 12 months..this is a job I want to attend to also,
Charlie

 

[Neverth]

Bought a weekend for spare parts quite a time ago. Failed "MOT" as it had no blower (no windscreen defrost is fail), auto ac.
Previoius owner had it run trough auto electrician and they diagnosed the PWM box.

I got there shorted the PWM box terminal (motor negative to ground) and the blower motor didn't work. The stupid electrician had not checked power.
Ghettorig from cig lighter (the PWM box was out as PO tried to find replacement), blower worked and I drove it home.
Temperature adjustment didnt work as AC ECU was in fault state and thought there was no blower, so there is no need to adjust the temperature.
First thing it donated was an AC line to get 155 Weekend to blow cold again.