Blower Heater 406 HDI 110 Rapier

[barrymurphy]

Hi,

My blow heater is not working and I have jumped the black and red wires on the two plugs that go into the fan control module and the fan works when the car starts. So I have power and the motor is fine. But left like that it stays on.

So main suspect would be the fan control module? OR is there something on the motor that the fan control module connects to that could be gone?

I got a spare control module from scrappy BUT there were two 406 HDis and the control module in both has green plug receptacles, one of which I took, but my control module has black plug receptacles and the ones available online are all green.

Is this black plug version specific to a variant? and can I wire the green one into my car? If so I do not want to do this wiring unless I am sure that nothing on the motor may be gone.

Thanks

Barry

[PeterN]

Certainly sounds like a controller fault and swapping the panel is by far the easiest way to repair it. Don't know about the different types though I'm afraid. If the connections are the same I don't see any harm in trying it.

Peter

[barrymurphy]

Thanks

When you say swapping the panel, do you mean changing the fan control module in the floor to the right of the motor?

I tested the fan button on the centre panel.

When I had the original control module plugged in, i tested the voltage increasing on a pink wire coming from control module as the fan button was turned up through the speeds. It went from 2 volts up to 14 volts. So it seems the resistance is working? Is this what you mean?

And if the control module was faulty and is just a resistor, would I not just have one speed?

I am concerned its something on the motor where the control module wires connects to. There seems to be something on the side of the motor when I look up behind the glovebox.

The control module plugs are slightly different on mine but both parts have the same part number. I can submit a picture later if it will help.

Regards

Barry

[PeterN]

I thought you were saying that you did not get a varying voltage on the control lead, if you do the fault must be in the module on the blower which contains two power transistors, they are normally what goes wrong, they don't always go s/c or o/c they can develop some weird faults.

Peter

[barrymurphy]

thanks.

I think that is what I should be looking at.

what does s/c or o/c mean?

In summary, the control module may be fine and the motor runs when control module bypassed
but with the power transistors gone she will not run when connected to the control module. Is this correct?

Can these be repaired or is it a blower from scrappy?

Regards

Barry

[PeterN]

Sorry. Open circuit or short circuit. If they are short circuit, which is often how power transistors fail, there will be zero resistance between the transistor connections, these sometimes go leaky which causes them to do strange things.

Peter

[barrymurphy]

thanks.

So blower from scrappy will fix it?

and is the following statement correct;

with the power transistors failed the fan will run when the control module is bypassed


thanks

barry

[PeterN]

That's probably the easiest way unless you are handy with a soldering iron.

The controller on the motor needs in input from the control panel to tell it what to do, as the voltage from the panel varies it changes the amount of power the transistors supply to the motor . With good transistors and no input the fan won't work at all although if you short the control lead (thin one) to earth the motor will run flat out.

Peter

[barrymurphy]

many thanks for your assistance, i will get the second hand motor and let you know,

regards

Barry

[barrymurphy]

sorry one more query,

is there a transistor in the footwell control module also or is it basically just a resistor?

want to make sure it is definitely not the footwell control module before i get the replacement fan

Thanks

Barry

[PeterN]

If its the same as the XM which I'm pretty sure it is there is a transistor regulator actually in the motor housing. A resistor type regulator will only give you a number of fixed speeds, if its fully variable it uses the transistor module.

Peter

[barrymurphy]

thanks.

my blower only has fixed speeds.

I was asking if there was a need to consider a transistor being faulty in the recessed control module, (it may not have one), before I change the blower motor itself which you have stated has two transistors attached/inside.

I have checked the recessed control module for varying voltage out and that is working.
So on balance the recessed control module is ok and its straight to the blower motor replacement?

Sorry if I am unclear, there are so many variables!

Regards

Barry

[PeterN]

If you don't have an electronic control panel what do you have to regulate the speed, is it just a rotary knob?

[barrymurphy]

thanks for sticking with me.

yes, a rotary knob.

[PeterN]

Ah right. As you were, that type of controller I am not familiar with, mine have always been of the transistor variety. I can't remember what the original fault was now Was it stuck on one speed?

Peter