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-   -   Fan switch built in ??? (https://www.the75andztclub.co.uk/forum/showthread.php?t=296635)

ferser1 16th June 2019 14:21

Fan switch built in ???
 
Dear members

I have a CDT 2.0 from 2005 and i noticed that one of the previous owners have built in a switch behind the steering wheel that operates the fan that cools off the radiator. So when i pull the switch (yeah its a pull switch) the fan spins which i believe is on the highest mode.

I also noticed that the airconditionin only blows cold air at idling when i switched on AC and when i switch on the fan manually.

When i switch only AC on, the radiatorfan does not spin when idling

The engine temperature stays at 90 steady all the time ,driving or when idle.

Now this is a huge hassle, turning on and off the fan at each idle moment, i would like to fix this so that it operates at is should and not manual.

I wonder what caused this situation that the previous owner needed to build in such solution.

How could i troubleshoot this problem??. I plan to go for holiday and this situation would not be ideal really..

Thanks

SD1too 16th June 2019 15:41

Hi Jan,

Your radiator fan's slow speed has failed. On a 2005 car the cause will almost certainly be a failed resistor. If you look through the radiator grille at about the two o'clock position, can you see a silver rectangular component with a wire at each end? That's the resistor.

The manual switch could have been installed for a number of reasons:
  • The owner may not have liked a garage's quote to renew the fan motor and control box (several hundred pounds).
  • The owner may not have known that such a simple remedy is available.
  • The owner may have been DIY minded but not keen on this particular repair.
  • Some people do strange things with their heating/ventilation/AC system, for example turning it off completely and opening windows.

Now you know that the solution is not too difficult. :}

Simon

ferser1 16th June 2019 16:20

thanks for the reply!

i remember i checked last week and i saw a golden colored rectangular component there, not sure if i saw the cables was quite dark spot, but are you referring to this component? Where can i buy a new one??

So in this case it could go either the cheaper way (replace gold colored component) or less cheaper way (replace control box) as far as i understood

I could do the replace resistor job , remove grill replace part but troubleshooting fan motor and control box sounds like a job for a garage , right?

Quote:

Originally Posted by SD1too (Post 2740992)
Hi Jan,

Your radiator fan's slow speed has failed. On a 2005 car the cause will almost certainly be a failed resistor. If you look through the radiator grille at about the two o'clock position, can you see a silver rectangular component with a wire at each end? That's the resistor.

The manual switch could have been installed for a number of reasons:
  • The owner may not have liked a garage's quote to renew the fan motor and control box (several hundred pounds).
  • The owner may not have known that such a simple remedy is available.
  • The owner may have been DIY minded but not keen on this particular repair.
  • Some people do strange things with their heating/ventilation/AC system, for example turning it off completely and opening windows.

Now you know that the solution is not too difficult. :}

Simon


Yorkshire GOC 16th June 2019 16:21

Quote:

Originally Posted by SD1too (Post 2740992)
Hi Jan,

Your radiator fan's slow speed has failed. On a 2005 car the cause will almost certainly be a failed resistor. If you look through the radiator grille at about the two o'clock position, can you see a silver rectangular component with a wire at each end? That's the resistor.

The manual switch could have been installed for a number of reasons:
  • The owner may not have liked a garage's quote to renew the fan motor and control box (several hundred pounds).
  • The owner may not have known that such a simple remedy is available.
  • The owner may have been DIY minded but not keen on this particular repair.
  • Some people do strange things with their heating/ventilation/AC system, for example turning it off completely and opening windows.

Now you know that the solution is not too difficult. :}

Simon

Jan,
If you have a silver resistor on your fan then you need to check if the resistor has failed - you need to do the "demist test" to checkwhether your slow speed fan is working or not - if the fan is not working you need to buy the upgraded gold resistor which you can get on E-bay.

Met beste wensen

Tenesmus 16th June 2019 17:06

Do these fan problems show up on a T4 etc?

SD1too 16th June 2019 17:43

Quote:

Originally Posted by ferser1 (Post 2740999)
... i saw a golden coloured rectangular component there ... but are you referring to this component? Where can i buy a new one?

Yes I am referring to that component but the gold version has a higher power rating making it more reliable. They are available from club trader Jules or e-bay.

I think some investigation is wise before buying anything. The control box isn't available on its own unless you buy second hand. A garage would normally fit a new MGR motor and control box assembly which is very expensive.
Quote:

Originally Posted by Tenesmus (Post 2741023)
Do these fan problems show up on a T4 etc?

T4 will confirm which speeds are not working. It seems that Jan's slow speed has failed since the fan does not run when AC is active, so I'm not sure what benefit T4 would bring.

Simon

ferser1 26th June 2019 15:07

I was just thinking, how could i tell that the problem is either the resistor or control box without replacing the parts / buying(and so testing/excluding/verifying if that was the problem)

SD1too 26th June 2019 16:29

Quote:

Originally Posted by ferser1 (Post 2743392)
I was just thinking, how could i tell that the problem is either the resistor or control box without replacing the parts ...

What you need to do Jan is find out how this manual switch has been wired. It may well be that the control box and/or resistor have been wired out of circuit. On the other hand the gold resistor may be open circuit, but that's unusual.
To do this, remove the bumper which will give you access to everything. Take a photo of any suspicious wiring and post it on this thread. Good luck!

Simon

Mike Noc 26th June 2019 17:57

Sounds like the control circuit has failed and been bypassed - easier to replace a failed resistor than bypass it. ;)



As Simon mentioned, whip the bumper off, trace the wiring from the switch, open the control box, take some photos and post them up on here and hopefully we can tell you what has been done and how to rectify it. :}


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