Faulty heater fan

[notajeep]

Hi Folkes,

1st post in the world of 406, previously stuck to Land Rovers, but go tired of fixing them! So here I am fixing a 406 instead!

Got a S-reg 406 Estate with what I would call climate control (ie temperature is displayed on LCD and all controlled by buttons)

When I bought it, the heater fan did not work at all. I removed it, and hard wired it straight to a battery (blck/red wires from motor) and it was dead. I promptly paid a visit to my local scrappy and removed what appears to be an identical fan from a more basic model (with out climate control). Tested it on a battery and it nearly took my hand off, so works well. Installed it and connected it all up and nothing. After a little playing with the buttons I discovered that it works on full blast (ie when using the manual button set with all the bards visible) but thats it. knock it down a level and it turns off completely. The buttons apear to work OK as the bars on the display are shown correctly, but nothing happens.

Is this a fault with the "control module" on the fan, or a fault with the climate control module? either way is it repairable? has anyone had the same thing? if its the CC module can I take it apart and repair the PCB/components in question?

Got to get it fixed quick as the wife will be using it in the evenings having just started a new job, and won't be very happy about having to sit in the either the cold, or gale force fan speed every time she uses the car!

thanks in advance

notajeep!

[puggy]

sounds very much like the fan control module and i believe you will need one
from a donor car with digital climate control for it to work properly ,dont
know about repairing one

[mjb]

Give me a shout friday - I may have one going cheap if you want to pick it up from Stoke (dependent on my dads car getting through the MOT without any major problems)

[notajeep]

I still have the dead fan that came out. It was the actual fan/motor that was dead, not (as far as I know) the control module, where the 4pin plug connects. I will have a play with it at the weekend and report back!

[paul]

My heater fan used to work fine (D9 GLX), but recently it is either on full (no matter what speed you set it to) or off. Sounds like a similar problem. Is there any easy way to check whether it's the fan or the control panel that's at fault?

[notajeep]

update....

during the few days of sun shine we had the other week, i got fed up with no fan, or gale force fan so had a furhter look at this.

I have now tried 3 different fans, and 2 different climate control units and I still have the same problem. Am I just really really unlucky??

I have noticed that the fan 'twiches' when the ignition is switched on with it set on less than full power, but thats as much as it does. (tested with the fan removed from its housing under dash)

I'm stumped!!!HELP!

[puggy]

viewtopic.php?f=1&t=4680&p=45250&hilit= ... tch#p45250

dont know if this will help but worth a try

[notajeep]

I'll certainly check it out, but I don't see why it would work reliably on full but nothing else....surely i'd get other issues too?
flaps all seem to work ok.

[mjb]

The fan gets a constant high current 12v supply and the CC panel basically tells it how fast to go, with that PCB you saw on the fan being responsible for the actual changing of voltage

From your post on Friday my guess is you've got a wiring fault between the CC panel and the blower.

Right I've just checked the Haynes. There's two wires you need to check.

Wire 8006 goes from pin 6 on the CC panel to pin 1 on the blower
Wire 8007 goes from pin 5 on the CC panel to pin 3 on the blower

[notajeep]

Hi mjb,

thanks for that I have had it all out again and check the wiring between those pins you gave and its fine (zero resistance)

Whilst I had it disconnected I checked voltage on pin 1 and 3 at the blower and found the following whilst changing the fan speed on the CC unit.

pin1 pin3
8.3v 0v fan on full power
10.8v 2.4v fan on all other intermediate settings (did not alter between various intermediate settings)
0v 0v fan off

any thoughts? Seems to me the CC module is still at fault as there is no variation on intermediate settings, but as I don't fully understand the circuit I'm not sure what results I should receive. I don't understand why the voltage changes on both pins....

thanks for your help so far!
notajeep

[notajeep]

Well another hot spell prompted another trip to the breakers yards and another climate control unit.

And the result is.... exactly the same as before... full speed and nothing else.

HELP!!! Its driving me mad!!

As a completely unimportant side question this CC unit in Farenheit not Celcius. Can that be changed?