Xantia Blower Fan Speed Control: Testing

[addo]

The slider control panel is in perfect condition. Unfortunately - as this means I need to investigate the climate ECU.

[addo]

Today I reached the end of this present investigation. Not saying the problem is cured, but some observations/comments:

1. Climate ECU is fairly easy to remove from below once you know how - just release the spring tab on the forward side and pull it down.
2. There were slight signs of antifreeze in the ECU box and oxidisation around some of the solder joints. On looking closely, I noticed what appeared to be a film of antifreeze/oxide under the bottom-most chip (a surface mount EEPROM).
3. The chip was desoldered, everything wiped clean with paper towel and boiled water then patted dry. Resoldering wasn't too hard with the heat gun set to hot with low fan, and a fine nozzle.
4. A final inspection under bright sunlight showed no further areas for concern.

A new ECU is about on par with the estate luggage blind - dear as poison. Fixes are well worth looking into!

[Axa]

My fan runs only at fullspeed, And only just after starting the engine.
After changing the transistors on the fan, its now possible to turn the fan of. But off or full speed is the only alternatives.
Betwene the thin wires (White and Orange) I can measure 7,5V when the fan is not running, and 8,2V at full speed.
What should my next step be? What is most likely. Faulty ECU or faulty speed regulator?

Best regards, Gunnar.

[Xaccers]

My fan runs only at fullspeed, And only just after starting the engine.
After changing the transistors on the fan, its now possible to turn the fan of. But off or full speed is the only alternatives.
Betwene the thin wires (White and Orange) I can measure 7,5V when the fan is not running, and 8,2V at full speed.
What should my next step be? What is most likely. Faulty ECU or faulty speed regulator?

Best regards, Gunnar.

Have you had the fan out to check that it actually isn't running?
They're pretty silent up until they are nearly running at full power.
If the fan is spinning at the lower settings, then it may be time to replace your pollen filter.

[Axa]

Yes, the fan is only going full or nothing. I was checking with the lid to the filter open.
And as said before. Only 7,5V or 8,2V in the orange and white wire. Any suggestions?

[uhn113x]

For those looking at this diagram in the Northern Hemisphere, please rotate your monitor through 180 degrees.

The diagram will also print upside-down but if you similarly rotate the paper through the same 180 degrees, it'll appear to be the right way up

Swap leads on scan coils or use a mirror from the pound shop to view it?