No heating/Air conditioning - Baffled

[Rhothgar]

Kenny. What vehicle is this on as a matter of interest?

I take it this is on your C5

[KennyW]

Yes, C5 x 7

[KennyW]

Quick update,

Check the blower earth line with +ve feed varied fan speed no change in voltage, light remained steady.

Did continuity check between pin 25 on ecu and blower module, continuity in wire.

It would appear to be an earth fault somewhere, but where is the problem ?

The search continues

Kenny

What is the climate control harness part no ? I have found 2 possible numbers 6436 H7 or 6436H8.

[KennyW]

Another quick update

Checked continuity between Line 1 on blower and line 3 on module fine approx 0.7 ohms

Checked continuity on signal wire between ecu and blower 27 ohms. Signal wire voltage when engine running 7 volts.

Checked continuity between earth point MC32 and blower line 4 27 ohms

Obviously 27 ohms is a small resistance but I thought this would be more like 1 ohm or less.

I am considering running new wires earthing wire from blower to module (line 1 to line 3 as per wiring diagrams).

Line 4 to earth on chassis.

I would like to do the signal wire but a little bit more tricky as Climate ECU is 26 pin connector.

I am NOT an auto spark so appreciate any thoughts.

Kenny

[KennyW]

Update

As Victor Meldrew would say I don't believe it ,

I thought I would purchase another Module unit but OE spec not Chinese spec, fitted today and Voila it's work properly.

Maybe as Marc said on page 1 be aware of the Chinese items. Simple lesson learnt.

Thanks to all that contributed to this thread.

Kenny

[GiveMeABreak]

Thanks for the update Kenny - that's another one in the eye for cheap Chinese crap.

[Hell Razor5543]

Something that is telling is that, when a manufacturer has a plant in Europe (for example) and another plant in China, the wealthy Chinese almost always prefer to buy the European produced item (even if the Chinese version is supposed to be identical in every way).

[admiral51]

Glad you got it sorted Kenny

[Armidillo]

Sorry I missed this back in November, where you mentioned replacing the blower module and finding the fan ran at one (slow) speed regardless of the fan speed setting.

I have had exactly the same experience with a Chinese sourced fan module for a 605 - it actually kept running at the same slow speed even when the control was set to "Off". When I complained the seller sent me another one with exactly the same result. Both looked identical to the original - no obvious missing components or joints not soldered on the circuit board.

I was lucky because I had access to a working fan module, which allowed me to prove that there was nothing wrong apart from the wretched module! Obviously mine is a much earlier design, probably bulkier, but no doubt the control logic is very similar to the more modern ones. There must be an electronic component that is quite expensive to manufacture even in China, so they solder in a fake one so it looks right.

Hopefully others reading this thread will be warned off "bargain" fan control modules, regardless of the age or model of their car!

[myglaren]

It is contra to the expected but I did buy two from China, one for each C5. Both were in and working when the C5s departed.
The dealer one, £130-ish, lasted about nine months.