Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Fresh Air Fan Resistor Pack

  • 28-03-2022 4:58pm
    #1
    John.G
    Registered Users, Registered Users 2 Posts: 3,623 ✭✭✭



    Decided to post on here as I reckon some excellent electrical knowledge on hand.

    Briefly, I have a 3 year old VW (polo) that has had 2 new replacement (under warranty) resistor packs, 3 in all with only ~ 14500kms total. I asked for investigation after second replacement but no joy so I decided to carry out a few tests today after removing the resistor pack. Should also say that these resistors are inserted in the fresh air fan ducting so are air cooled. The fan will only then run in speed 4 when the resistor pack fails. It will also run in speed 4 if your remove the pack terminal block.

    The pack is fed from the fan switch and the terminals are numbered 1 to 4 from right to left. The numbers below are self explanatory, but terminal 4 which in speeds 1,2&3 is the ground wire but becomes live (12V) when the fan is switched to speed 4, can someone give a explanation for switching this wire to Live, bearing in mind that the fan will run on speed 4 without any resistor pack or wiring harness and also any comments on the unacceptably very short pack life. (The pollen filter was changed).


    Polo Fresh Air Blower Wiring.docx


    image.png


    My Polo Resistance Pack..jpg




Comments

  • #2
    [Deleted User]
    Posts: 0 ✭ [Deleted User]


    These resistor packs have a built in thermal fuse which is probably what is failing. The reason it is likely to be failing is because the fan itself is catching and the excess current is blowing the resistor pack fuse.



  • #3
    John.G
    Registered Users, Registered Users 2 Posts: 3,623 ✭✭✭John.G


    Polo Fresh Air Blower Wiring.docx


    image.png


    My Polo Resistance Pack..jpg


    No, not catching because you can turn the fan impeller quite easily with 2 fingers with filter removed.



  • #4
    John.G
    Registered Users, Registered Users 2 Posts: 3,623 ✭✭✭John.G





  • #5
    zg3409
    Registered Users, Registered Users 2 Posts: 7,035 ✭✭✭zg3409


    It seems to be a common faulty unit and the replacement also seems to be unreliable.

    The resistor pack is "bypassed" at full speed as it's not needed.


    Often certain cars or the parts have known issues and replacing the part with like for like is likely to cause the same issue down the road. Over time they typically bring out a new version that fixes the problem, however on cars with only 3 years warranty it soon becomes your problem.



Advertisement