DS4 heater blower

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Jimmy Ellis
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DS4 heater blower

Post by Jimmy Ellis » 21 Oct 2019, 13:04

DS4 heater blower not operating. Plugged a new blower resistor in. Nothing. However metal work on resistor touched chassis, blower burst into life. Can anyone explain. Motor doesn't seem to be getting negative supply. Can't source any wiring diagrams.

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myglaren
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Re: DS4 heater blower

Post by myglaren » 21 Oct 2019, 13:36

Post your VIN so we can see in more detail but it is almost certainly a bad earth.

Jimmy Ellis
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Re: DS4 heater blower

Post by Jimmy Ellis » 21 Oct 2019, 13:46

VIN no. Is VF7**************[VIN obfuscated, can be read by forum staff].
Do Citroen use yellow and green coloured cable as earth because nothing between chassis and said cable on resistor plug.

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GiveMeABreak
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Re: DS4 heater blower

Post by GiveMeABreak » 21 Oct 2019, 15:08

Leave it with me - I'm working through posts and catching up - I'll take a look shortly.

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GiveMeABreak
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Re: DS4 heater blower

Post by GiveMeABreak » 21 Oct 2019, 15:37

Unfortunately, a lot of the wire designations are not know - but on the diagram below:

8050 is the Blower Motor Module (where separate) and you can see that the earth MC46C connects via the interconnection harness to 039 at pin 4 which then goes to the blower module pin 6. So that is likely to be your earth - and the power looks to come from JG10 via fuse F10
DS4.PNG

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Re: DS4 heater blower

Post by Jimmy Ellis » 21 Oct 2019, 16:47

Pin 4 027 when a continuity meter put between pin and chassis no continuity. Where is 8080 located.

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GiveMeABreak
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Re: DS4 heater blower

Post by GiveMeABreak » 21 Oct 2019, 16:53

Bear in mind that 8080 is the Air Conditioning ECU and these wires will not be live all the time - some of them are command wires.

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Paul-R
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Re: DS4 heater blower

Post by Paul-R » 21 Oct 2019, 17:21

Now that you have made the blower work by connecting to earth try refitting the control unit and seeing if the A/C works. I would give it another "go" with the earth connection first.

It sounds similar to the problem that exists on the X7 C5, in fact mine suffers exactly this symptom. I leave the car alone for a while (I don't drive it as much as I used to) and then the A/C blower doesn't work. If I take the control unit out and take a jump lead to an earth (the control unit is on the earthy side of the motor - the motor is fed with 12v) this applies full power to the blower motor and gets it going. Refitting the control unit I then find that the A/C blower now works.

It is theorised that the motor spindle is a little rusty or gummed up and the slow start that the control unit normally operates won't overcome the stiction of the shaft. Once that is broken then a soft start is OK.

It's also possible that the control unit is not working at its best and shutting down at an earlier point than it should do. Some people have found that a new (not Chinese!) control unit brings the blower back to life.

Me, I just do the jump lead to get it going. If I'm driving the car regularly the problem doesn't happen.

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Re: DS4 heater blower

Post by Jimmy Ellis » 22 Oct 2019, 17:34

Big thank you too the team, Marc. Connector 10 PR/59 was faulty.(burnt out). Remade. Blower and heater all good.

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GiveMeABreak
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Re: DS4 heater blower

Post by GiveMeABreak » 22 Oct 2019, 18:54

Excellent - well done and thanks for the update - will certainly help others in future :-D