stop light flashiing with Aircon on

[womcat]

Hi all,

Have been trawling through the forum to try and find info on an Air Con/coolant blower problem without success. Here's the story:
I have a 1999 2.0 HDI diesel (GLX model - D8 I think). The Air Con didn't work when I bought it but finally got round to having the condenser replaced and system re-gassed. Once this was done a problem showed up. Neither of the fans (twin fan model) come on when the AC is turned on, either on auto or aircon setting. After a few seconds the STOP light stars to flash. I guess the ECU thinks it has no cooling. If the setting is switched to eco (no aircon) then all seems well. If pin 2 on the centre relay is earthed then both fans run at slow speed. If the blue connector, which I believe is the engine coolant sensor is unplugged the the left hand fan (if you are standing in front of the car facing it) runs at full speed when the ignition is turned on. Everything seemed to point to the engine coolant control module (bitron?) not supplying the earth. Went looking for the bitron in the nearside front wing as per every post I've read. Nothing there. Not even a place/plug where it could have been. Went to the local dealer and asked for a price on one (just to see what it looked like). He said according to the VIN number which I gave him my model doesn't have one, nor does it have an air conditioning control unit. More than that he couldn't/wouldn't say.

Come to think of it, as the HDI seems to run so cool, don't even know if the fans ever worked as they are supposed to, regardless of the AC problem. I have rotated the three relays so each is now in a different spot. No change.

Internal blower was intermittent, but repaired burnt red wire and now works fine.

Sorry for the long post but I'm tearing my hair out over this (what little hair I have)

Has anyone else had any problems in this area? Any chance of a schematic/circuit diagram (even hand drawn), anything to help point me in the right direction. Haynes says it has an engine coolant control module, so it is obviously no use for this problem.

All suggestions appreciated

[DickieG]

Has anyone else had any problems in this area?D

Yes look at this post.

For a wiring diagram look at this post.

[womcat]

Thanks for the reply.

I didn't spot the first link when researching the problem. I will go and see my local friendly garage tomorrow and get them to reset any fault codes. Maybe I'll get lucky.

The second link you gave only gives the wiring diagram for the 306, which uses a "cooling fan control unit" (bitron?) which my model doesn't seem to have. I did read through this post before, which made me look twice at the internal blower (used to be intermittent). Funnily enough when I disconnect the internal blower motor the stop light doesn't flash anymore.

Will post update regardless of outcome tomorrow

[mark21td]

There is some info on www.406co.co.uk about cars without a briton unit.

[womcat]

Well, I ordered a code reader from the bay of fleas. However, with the present postal unrest I don't know when it will arrive, so got my friendly garage to clear the codes for me, which they kindly did free of charge. Unfortunately the stop light started flashing again seconds after starting the engine up. In other words, no change.
Had a look on the 406 owners club forum but couldn't find anything except for models which had a resistor in the fan cowling, which my doesn't have. Could REALLY use a schematic or circuit diagram for this model. Can anyone out there help out?