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[Mike Collins]

A few days ago my blower fan ceased to run on my 2.6. Fuse 33 is intact, at 30A I would have thought something dramatic would have caused failure.

Today I started to dismantle and check, power is available at the fan controller, the control lines have a change in voltage with fan speed command.

I removed the controller and dismantled it, what a change from earlier versions.

There is now only one component mounted on the heat sink, no obviously failed parts.

I did try running the fan with external 12V as I was concerned that excessive current demand may damage or cause the controller to shut down.

Applying external power it took just over 10A and was a bit noisy, which I remembered it doing from cold when the fan still ran.

Reluctantly I removed the fan assembly, this is not fun, cleaned and lubricated`the bearings as far as possible and retested. Still just over 10A draw.

I have just reviewed Taxi Driver's post of a similar problem, until then I was convinced I had a controller failure.

Has anyone measured the running current on 12V? Tomorrow I need to risk ordering a controller, any ideas?

[Kevin Wood]

I'd say 10A is about what I'd expect from a  fan running flat out. The controller is probably the problem. If you could post a picture of the innards it might be possible to say if they are repairable. Sounds like it's just a transistor gone but I've never seen such a device. :-/

Replacing a transistor is likely to be much cleaper than sourcing a new module from VX....  

Kevin

[Taxi_Driver]

Hmmmm sounds familiar.......

When my fan failed it would run with external 12v but not when attached to speed controller.

You have proved 12v going to speed controller and signal wire from climate panel steps between 1v and 5v (I think this is the range, carnt remember!)

Now can you check the output voltage from the speed controller when the fan is connected and also disconneted.

In my case the output was 0v with fan attached and stepping voltage to 12v with it disconnected.

My fan was trying to take too much current than the controller could supply.....it was slightly stiffer to rotate by hand than the replacement i put in.

But either way forgot Vx for replacements.......iirc about £100 for a new controller and about £170 for a new fan assembly.......Go scrappy hunting.....
My replacement came outa a 2.0 GLS for a tenner  
Tho there a two different types of fan assemblies so take the old one with you......also do what i did.....before paying for the fan/controller plug into your omega to check it works  

[Mike Collins]

Kevin,

I have to say I was reasonably happy with 10A uncontrolled, until I read Taxi Drivers thread.

The module is completely different from the earlier version I had in a 97 2.5, that had three power MOSFETS that failed short circuit and could be replaced.

This newer version has only one, unrecogniseable, power device that is surface mounted on the heat sink area of copper, I'm not sure I could unsolder it. The main finning is also very different, it has long, conical fins.

I'll try to post up some pictures.

Taxi Driver,

Finding your original thread started me questioning the idea of just controller failure,
the idea of overcurrent shutdown seems reasonable.

Removing the fan is no picnic is it?

Has anyone ever had the need to measure the fan current?

Thanks for your thoughts.
Mike

[Marks DTM Calib]

Its a later integrated contoller/power chip......either of the controllers can be used as they are compatible.

The later version has an over current shut down it would appear..........

[Mike Collins]

Update on my fan failure, as Taxi Driver says, 12V at fan output of controller when open, 0 when fan connected.

Tried another controller, no change. Now it gets interesting or confusing.

It dawned on me that I was doing these changes with F33 in place, so power on to controller. Powered the system off completely, then connected a headlamp bulb in place of the fan, refitted F33 and.....

Lamp at varying brightness with fan speed selection, current draw up to 3A or so.

Refitted fan, speed controllable, draws up to 6A at max available setting. Same with both controllers.

I don't really know what conclusions to draw from all this, the only changes were lubricating the motor bearings and refitting the controller with power off.

Fan motor no longer squeaks, plus point.
Running current is up to 6A or so.

For anyone attempting a fan change, it's a heck of a lot easier to remove the air duct if you remove the passenger's air bag and its mounting.

The only other information is main dealer in Bristol has three controllers in stock with a significant usage rate.

[Taxi_Driver]

So... i assume its working ok now?? ....not sure why tho....if you havent changed anything  :-/

And yes its a PITA to change the fan blower.....

Took me 6 hours all in........

I removed the side air vent....air bag (well nearly...i made it very loose....disconected it tho) air vent pipe and took out wiring loom tray .....PITA job......but got there in the end  

Maybe yours was just stuck........theres weights on the blower fan blades to balance the fan......maybe one of them had dislodged and caused the fan to stick  :-/

[Marks DTM Calib]

But you have changed something......you lubed the bearings.....which will exert less load on the fan and hence a lower current draw.

[Mike Collins]

Yes, lubricating the bearings appears to be the only significant change, current draw with the battery directly connected didn't change much though.

The battery had become quite discharged by this time, so conditions were not identical.

As you say, it's working and I have lost the squeak, I'll wait and see what happens next.