Heater Blower Fan works on setting 1 only

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My Name: ttleader

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Posts: 3
Joined: Fri Feb 08, 2013 2:41 pm

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Hi there.
I have just brought a 2003 c3 diesel with manual heater controls and a/c.
The heater works on setting 1 only. The a/c button seems to work as do the recirc. button and the heated rear screen button.

I have checked all the fuses in both the engine fuse box and the glove box. There does not seem to be a relay to check.

I have changed the resistor pack at the rear of the heater in the drivers foot well...but no difference.

I noticed on the forum that the connection B6 at the rear of the heater control switch should have 12v.
When the switch is set to position 1 it does have 12v and the blower runs ...this goes off when I select positions 2-3 and 4 as does the blower.

I have dis-assembled the switch unit and cleaned the contacts inside the unit....no difference.

When I was putting the resistor pack in I briefly earthed the edge on the brake rod ...the motor sprang into life.

I have followed the procedure for resetting the ECU/BCU...again no difference

I'm at a bit of a loss what to try next ....does anyone have any suggestions?
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My Name: C3CAR

Guru
Posts: 2706
Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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Been thanked: 99 times

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I noticed on the forum that the connection B6 at the rear of the heater control switch should have 12v.
That's for the petrol engined C3, the diesel has different wiring for the air conditioning,

If the fan runs on one setting, then the input voltage, relay (in the engine bay fusebox) and fuse F8 are going to be ok, so no need to check them.

The fan speed is selected by the control panel and the voltage is reduced by the resistor pack.

You can check the resistor pack for resistance and you can check the control panel switch actually switches (by measuring the resistance) and measuring the output voltage when its connected.

There is a diagram in the C3 Haynes Manual which will help you find some test points to find the fault.
My Name: ttleader

Member
Posts: 3
Joined: Fri Feb 08, 2013 2:41 pm

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Many thanks for the info in your reply...I'll make a start if it ever stops raining and report my findings

Just a thought...do you happen to know if the switch units are the same for the petrol and diesel?
My Name: ttleader

Member
Posts: 3
Joined: Fri Feb 08, 2013 2:41 pm

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Since my last posting I have checked the outputs from the heater blower switch positions 2,3 and 4.
As these were "dead" I've located a replacement heater control panel. Mine is the diesel with manual controls and A/c and second hand panels are rare. (three knobs and 3 buttons at the top)
Now all blower speeds work fine.
Thanks for your support.
ttleader
User avatar
My Name: C3CAR

Guru
Posts: 2706
Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
Has thanked: 186 times
Been thanked: 99 times

Post

Now all blower speeds work fine.
That's great news! Well done and thanks for the update!
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