xf1ref wrote:1. The heater/blower on my car is running fine, but when is in the position auto and I press the break pedal, the rotation speed of fan is increasing.
I checked the conectors from the fan, the green relay under the dash, I even put a relay on key switch on brown plug. Other Xantia owners from my country don't have this issue. What is the connection between the heater blower and break lights circuit? Is there a solution for this issue?
I don't think there is anything particularly unusual about this - on both of the Xantia's I've owned the fan speed if on a medium speed increases somewhat when the brake pedal is pressed - I believe the cause for this is that the control voltage from the climate control ECU to the fan works in a reverse sense - eg a high voltage commands slow speed and a low voltage commands high speed.
Pressing the brake pedal turns on the stop lights and causes a voltage drop which affects the supply to the climate control ECU which reduces the voltage output on the control wire to the fan slightly which actually causes the fan to speed up.
As long as the speed change isn't large I wouldn't bother about it as you could spend a lot of time hunting for a fault that isn't a fault but really just a design limitation. (Under rated / too thin wiring used in the electrical system)
2.In the past time I've seen that when I turn on the heated rear window and mirrors the dashbord light is weakens. Recently I mounted at car a ceiling lamp from laguna II (I'm not sure for this thing name
). In this I mounted a green minivoltmeter.
Last night it was fog in my town and I use in addition for dipped beam the fog lights. When I switch on heated rear window and mirrors I noticed a drop of voltage on minivoltmeter...down to 11.6V. The engine was at idle speed ~900rpm and if accelerate up to 1500rpm the voltage increases up to 13V. I checked with a multimeter on battery terminals and same voltage.
Definitely something wrong with your charging system - it should be able to maintain at least 14 volts with headlights/heated rear window etc turned on even at idle.
I checked my Xantia only a few days ago and found that with heated rear window on, cabin blower fan on fast, A/C on, headlights on dip, front fog lights on and engine at idle (650 rpm on a V6) it was maintaining a steady 14.15 volts at the battery posts. Optimum range is 14.0 to 14.4 volts with the engine running.
Even 13 volts is far too low with the engine running, let alone 11.6v. If its dropping this low it could well cause the issues you see with the brake pedal affecting fan speed excessively.
First thing I would do is check your accessory belt is tight and not slipping, also Citroen engines are known for the harmonic balancer rubber in the crank pulley to fail - it begins to slip under load, sometimes causing a squeak/squeal and sometimes heavy steering at idle.
Draw a chalk line across the side of the crank pulley from metal to metal across the rubber and check it a day or two later to see if the chalk line is still straight - if not you need a new crank pulley ! (Even if it isn't the cause, or whole cause of your low voltage)
If the belt seems tight and crank pulley is ok you probably have a faulty alternator or wiring from the alternator to the battery.
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