How does automatic climate control in 306 work?

The 306 is getting on, and things do happen with ageing machinery. Electronic controls tend to be mysteries to most people.

Here is the heater/AC wiring for one of the 306 models. 8080 is the ECU for the unit, and the fan controller, fan, mixing shutters are along the bottom. The cabin fan-thermometer is 8030.
ventilation chauffage diesel.jpg
 
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IDK how it works as I’ve never used the auto setting on my 306 but my AC is cold and my heater is toasty.
 
Hmm. I feel like a school teacher correcting someones homework.
But like a Pink Floyd-esque teachers' comments, they are probably nit-picky and irrelevant.
The diagram of the "passenger compartment air thermistor"(8030) is drawn incorrectly, at least considering where the wiring goes.
Should look like this:
ventilation1.jpg

The free wheeling diode across the coil of the compressor control relay (8005) is drawn around the wrong way. OR the wires C128 and 1234/8075 are drawn transposed?
ventilation2.jpg

The coil of the compressor is driven directly from the air conditioning ECU? Fuse F21 seems to be doing all of the heavy lifting for the aircon system including the compressor clutch coil and the interior fan!
I was just trying to interpret the aircon operation from the diagram when I came across those anomalies. As I said before, they won't effect the solving of the original posters' problem...just saying.
Thanks for the diagram Seasink.
 
It's a copy from a French service manual. I haven'r really looked at, but hoped it might be useful.

It looks to be an official PSA diagram.
 
ozVTR said:
Hmm. I feel like a school teacher correcting someones homework.
But like a Pink Floyd-esque teachers' comments, they are probably nit-picky and irrelevant.
The diagram of the "passenger compartment air thermistor"(8030) is drawn incorrectly, at least considering where the wiring goes.
Should look like this:View attachment 227669
The free wheeling diode across the coil of the compressor control relay (8005) is drawn around the wrong way. OR the wires C128 and 1234/8075 are drawn transposed?
View attachment 227670
The coil of the compressor is driven directly from the air conditioning ECU? Fuse F21 seems to be doing all of the heavy lifting for the aircon system including the compressor clutch coil and the interior fan!
I was just trying to interpret the aircon operation from the diagram when I came across those anomalies. As I said before, they won't effect the solving of the original posters' problem...just saying.
Thanks for the diagram Seasink.
Click to expand...
You are correct on both counts fellow pedant :)

The flyback diode is shown reversed to the diagram printed on the relay itself, fused +12v on pin1 and pin2 (8075) of the relay coil gets earthed via pin 11 of the Bitron Cooling Fan controller (8010).
F21 A/C and Ventilation is 30Amp


306AC.jpg
 
Enjoy this lot for the 306. Who knows what else is odd?
vdocument.in

Peugeot 306 Wiring Diagrams - [PDF Document]

PEUGEOT 306 - ENGINE TYPE: TU3JP/L3 - INJECTION/IGNITION SAGEM SL 96 / TACHOMETER / ELECTRICAL SPEEDOMETER - WIRING DIAGRAMS PEUGEOT 306 ENGINE TYPE: TU3JP/L3 INJECTION/IGNITION…
vdocument.in vdocument.in

These also look to have been uploaded from a PSA source.

They also show up here

Peugeot 306 Wiring Diagrams [q6ng185wyjnv]

Peugeot 306 Wiring Diagrams [q6ng185wyjnv]. ...
idoc.pub idoc.pub
 
My 2003 C3 has a 40 Amp fuse dedicated to just the interior blower fan! AND I have seen that fuse and holder reduced to carbon on a BSM! Sure, having a lower rated fuse will better protect the circuit but it just seems bad engineering to put all your eggs in one basket.;)

Seasink, I'm sure the circuit diagrams are kosher, they look "real" to me. I was certainly not casting any aspersions on you.

I'm not having a go at anyone here and I apologize if I have hijacked the OP's thread. I'm just stuck at home with an infected jaw, pain and nothing better to do.:)
 
I am not aspersed, I'm puzzled, so I checked the source. The 306 posted is for a "berline diesel"..
 
The a/c in my daughters 2001 306 Rallye works remarkably well. The only issue we have is the fans aren't cutting in when the temp get's up above 90-95 degrees. I've been trying to daignose and fix this for some time (installed new temp sensors, checked relays/wiring, new bitron unit) but still doesn't work. We just drive round with the a/c on all the time which runs the fans at half speed and that keeps the temp under control. Thanks for the wiring diagrams will have another go at fixing the issue.
 
matara said:
The a/c in my daughters 2001 306 Rallye works remarkably well. The only issue we have is the fans aren't cutting in when the temp get's up above 90-95 degrees. I've been trying to daignose and fix this for some time (installed new temp sensors, checked relays/wiring, new bitron unit) but still doesn't work. We just drive round with the a/c on all the time which runs the fans at half speed and that keeps the temp under control. Thanks for the wiring diagrams will have another go at fixing the issue.
Click to expand...
As per a previous reply, behaviour you see is normal. Because the temp guage goes over centre when stuck in traffic it looks like a problem but it's because with the black faced Bitron the High speed fans won't kick in until a tad over 100 deg C (but before the redline) which with the pressure of a working radiator cap is NOT yet at boiling temp. There is a (rare) green faced Bitron that will start the high speed fans at a lower temp. I bought a 306 with 'blown head gasket' because owner had to keep filling the radiator, turns out the A/C had leaked causing the behaviour you describe and they were always overfilling the expansion reservoir on side of radiator because the MAX line and MIN line is very hard to see and is NOT the water level in the radiator. On stinking hot day I put a bottle under overflow pipe and I let this car idle and high speed fans came on below red line and temp dropped to 95 and once reservoir water level was about half way no further water was overflowed as it repeated the cycle for 20 minutes. Once cold the level was still above the MIN line so that's were I left it.

To confirm Bitron is working, with ign on if you disconnect the brown temp sensor after a few seconds you'll hear fans on low speed and a few seconds later both fans on full speed, reconnect and they'll turn off.
 
matara said:
The a/c in my daughters 2001 306 Rallye works remarkably well. The only issue we have is the fans aren't cutting in when the temp get's up above 90-95 degrees. I've been trying to daignose and fix this for some time (installed new temp sensors, checked relays/wiring, new bitron unit) but still doesn't work. We just drive round with the a/c on all the time which runs the fans at half speed and that keeps the temp under control. Thanks for the wiring diagrams will have another go at fixing the issue.
Click to expand...
Sadly I don't think this circuit diagram is going to help you.
I'm not familiar with this car but from what I can see of the diagram above, you will need a circuit with the rest of the "8010: coolant temperature unit" in it. I.E. an engine cooling circuit diagram.
From what you say, the parts covered here, are working.
 
Not wanting to hijack this thread let me know if I should start another one, but already done the check of unplugging the brown connector on the thermostat switch and fans come on slow/half speed for a few secs and then speed up to full speed and stay on until I plug it back in! This indicates the relay circuit is working.
 
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