No heating/Air conditioning - Baffled

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Excellent Marc, I have removed that panel before whilst routing some wiring. Nice to see the access, will report back what happens next.

Kenny

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Replaced the heater module no change.

Will have to check for supply to heater blower ?

How easy will it be to check the supply from fuse box in engine bay ?

Citroen electrics are an interesting conundrum :rofl2:

Just looked at where the H.B. is and I wondering how I'm going to get my hands there to remove it ? :rofl2: :rofl2: :rofl2: :rofl2: :rofl2:

This definitely a 5 star rolf.

Kenny

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GiveMeABreak
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Re: No heating/Air conditioning - Baffled

Post by GiveMeABreak »

I put up the specific part for the heter blower removal here Kenny:

viewtopic.php?p=595211#p595211

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Thanks Marc,

Once again upside down in the footwell, then twisting myself to bits just have a look at the blower. :rofl2:

or the BOL's method remove dash and check :roll:

Kenny

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Looking to confirm part no for the fuse box in the engine bay, I have the following number 96 758 779 80

Kenny

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Re: No heating/Air conditioning - Baffled

Post by GiveMeABreak »

You need part: 9807028580 Kenny (Item (1)). £232.19 inc. from Citroen.
image_2020-11-20_102856.png

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Thanks Marc,

Here's the latest, heating is working but the blower is running at 1 speed only. At least it's clearing the windscreen.

Kenny

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GiveMeABreak
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Re: No heating/Air conditioning - Baffled

Post by GiveMeABreak »

Dare I ask what brand / where you got the heater blower control module from Kenny? The fact that it is operating at suggests power, so I would still be suspecting hte blower control unit - these have been know to arrive dead on arrival - and quality of parts is extremely variable, with some (notably from ECP) being the worst.

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

It's made in China, with no makers name on the box bought off ebay.

Any recommendations.

Kenny

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Re: No heating/Air conditioning - Baffled

Post by GiveMeABreak »

Yes Hella - they are not the cheapest though, but are OEM quality Kenny.

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Thanks Marc,
I couldn't read the name properly but that's what came off. I had a look inside and it is a small circuit board inside with lots of very small electronics, nothing obviously wrong.

See Pics


Kenny
IMG_0099.JPG
IMG_0100.JPG
IMG_0101.JPG
IMG_0102.JPG

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Well I got hold of a 2nd hand fuse box and fitted same no difference, as the blower is working 1 setting does this imply the air blower is working correctly and the problem is with the module.

I will find out another module here ready to fit.

Kenny

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Re: No heating/Air conditioning - Baffled

Post by admiral51 »

I thought i had replied earlier but seems i pressed wrong button :(

Somewhere deep in the old grey matter i seem to recall i had a similar issue with no blower but everything showing lit up on the old Devil Car after it had been sat for a good few weeks.
I did not change the control module as i just bridged the plug to give full power on start up to kick start the blower itself.
From memory the module increases voltage ( power ) to the blower and the blower motor itself can become sticky and only operate on slow or not at all.
By bridging the plug to full power it can kick start the blower and once done it can behave as normal ?

Probably wrong but just my grey matter kicking me.

Colin

*****EDIT*****
I have done a bit of digging and found My Blower Thread . Maybe of some help or not

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Re: No heating/Air conditioning - Baffled

Post by GiveMeABreak »

I'm not sure if this will help at all as if you are getting at least some speed then at least a signal is getting through. If there are no fault codes being picked up with the Climate ECU then it won't be in backup mode. The original Blower Control Motor is made by BEHR.
blower motor graph A.PNG
"a" Control voltage.
"b" Time.
"A" Period n° 1.
"B" Period n° 2.
The cyclic ratio is equal to : Period n° 1 divided by period n° 1 plus period n° 2 (Ratio of approximately 10 % in this example ).
blower motor graph B.PNG
"a" Control voltage.
"b" Time.
"A" Period n° 1.
"B" Period n° 2.
The cyclic ratio is equal to : Period n° 1 divided by period n° 1 plus period n° 2 (Ratio of approximately 50 % in this example ).
image_2020-11-25_181340.png
image_2020-11-25_181340.png (99.03 KiB) Viewed 22 times
"c" Average air blower motor control voltage.
"d" Reference value received by the digital air blower control module.

The Blower motor is the OCR type and the control voltage works on a scale of 0 to 14.
The value of the cyclic ratio of the control signal makes it possible to define the power requested by the vehicle’s passengers.
image_2020-11-25_182358.png
Allocation of the channels of the black 4 -way connector
Channel No.Designation
1Earth: Digital air blower control module
2Air blower motor control
3Earth: Air blower motor
4Digital control

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KennyW
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Re: No heating/Air conditioning - Baffled

Post by KennyW »

Thanks Marc and Admiral51,

I checked again with Diagbox and got a fault code for Airblower and on expanding code it stated intermittent fault with blower. Can't remember complete code but it was either F70** or F72**.

But I was going to remove blower and put 12V direct from battery to see if it would work.

I'm going to read and digest your info Marc to understand how the module works.

Will update tomorrow.

Kenny