C5 X7 2008 Blower Control Module

[admiral51]

So maybe the designers of the product have tested how it works over a set number of hours to see how it stands up to constant use, but maybe and understandably have not tested it after a period of prolonged daily use and then left idle for 2 months ?
They assume it gets used daily so maybe a 7 day interlude would be industry standard test ?

[white exec]

Allegedly, our cars are tested to temperatures down to -50°C or so, but that won't show up the cumulative effect of age and dried-out bearings. In any case, such things represent future spares income, so of it fails somewhere in the 5-10 year slot, it will be regarded as having done its job, and maybe accepted likewise by most owners.

[admiral51]

Allegedly, our cars are tested to temperatures down to -50

But then we as individuals should be asking the questions of what the car did before and after the test, but we do not we accept that the MPG reported is worthless info yet we still buy them lol

[Paul-R]

In related news: I took my C5 out for a run today after leaving it parked up for the last month. Naturally the blower didn't start up and I had to run through the "process". Only takes me 5 minutes (with absolutely NO need to remove the glovebox or lid) nowadays and then it was up and running again.

[white exec]

You must be only a whisker away from a handy "Blower: Push to Start " extra button on the dash!

[GiveMeABreak]

God forbid if I ever had one of those! A nice Key will do thanks.

[Paul-R]

Huh? Push to start the heater fan blower not the car Marc. And yes, its appearance is perilously close.

[white exec]

(and no, it's not mine!)

[Greg2791]

Hi,
I was thinking about the issue again and conclusion is that in my case it was seized motor.
The module has built-in soft start.
When I took out the module it was getting hot (it means that the current was flowing by) so I added a wire pushed in with the black one (also wrapped both together with electric tape) ended with the WAGO 222(isolation) on the other end, hidden under the cover (right leg passenger ankle). In case the motor seizes again It will be few second to open the cover(one screw only) and short it to the GND.
But the button looks cool, 007 like rocket launcher.
Now when I know where to module is located - no need to take out the glove box - however to do all test I did it was necessary. A lot of learning.
Thanks for help, I hope my posts help other too.

[white exec]

The idea of a 'kick-start switch' was meant tongue-in-cheek, of course.
The decent solution is to free up and lubricate the partially seized motor, or the problem will only get worse.
Interesting that the module has a soft-start, which, although good in itself, is just what you don't want if you're hoping to free-off a sticky motor.

I don't think it's good practice to regularly start any of these (or many other) motors on full speed with full supply voltage on tap: the initial current in-rush is huge. One practical tip is not to leave fan controls on full speed, and then start the engine! Running current at maximum speed for some of these blower motors can be 20-25A, and momentary starting current can be several times that.

[Paul-R]

The idea of a 'kick-start switch' was meant tongue-in-cheek, of course.

Many a true word spoken in jest.

The decent solution is to free up and lubricate the partially seized motor, or the problem will only get worse.

Probably but it ain't going to happen in the near future.

I don't think it's good practice to regularly start any of these (or many other) motors on full speed with full supply voltage on tap: the initial current in-rush is huge.

Hmm, I hadn't considered that. But, hopefully, it wouldn't be on a regular basis.

One practical tip is not to leave fan controls on full speed, and then start the engine!

I don't think that would work as the controls don't actually control the motor. They merely make a request that climate control ECU considers!

[myglaren]

I don't think that would work as the controls don't actually control the motor. They merely make a request that climate control ECU considers!

My son will frequently come from work and leave the blower on full (manual) and it does start up full-tilt.
If the 'clear screen' option is used, this drops out when ignition is off and the CC returns to automatic mode and gradually increases fan speed as required.

[Greg2791]

I don't think it's good practice to regularly start any of these (or many other) motors on full speed with full supply ....

It happened to me 3 or 4 times so far in 2 years so no big deal. It fixed itself before - after couple of days(not the last time) Previously it was heating up itself(module) and motor without any air flow. Just 1 sec full supply will not be worse. If someone is overcautious it could be done via 12 V high power bulb(2x55W in parallel)

BTW, how to take out the blower motor?

[Paul-R]

A world of pain probably. I suspect dash out for a start. Not a trivial task if it is.

[GiveMeABreak]

No need to remove dash Paul.

Similar trim removal to get to blower control module and a few air ducts, then there is access to the motor, a few clips and a clockwise turn I believe from memory, but if anyone wants to know I can get the fuller detail. Obviously a lot more work in a left hand drive, as driver knee airbag and steering cowling, some of the pedal assembly needs removing IIRC but none of that on a RHD.