Question about 307 cable and radiator water temperature

Hello friends, in my 307 1.6 automatic car, there is a socket coming out of the harness on the back of the right headlight. Does anyone know what works?

I have one more question I went about 100 km at 5 degrees air temperature, the temperature indicator did not even reach 70 degrees. Normally it was stable at 70 degrees at 20-25 degrees air temperature. Since the air temperature is low, it may be low in temperature, but shouldn't the car be around 90 degrees? As a result, the engine will be heated in cold weather and the heater will be heated. I wonder if there is a problem with the thermostat? I also have a photo of the indicator. canbulat55 2015-11-10 18:33:56

There may be a problem with the thermostat, when I used the vehicle, it was like early morning. because when I come to work in my car in the morning, it doesn't exceed 70 degrees. I don't know the socket in the lamp.

It was between 8-9 pm. Let's change the thermostat, let's see, it's already been 4 months since the vehicle has already looked at the previous owner.

Friends said I need to take the thermostat from the particle and replace it. I said the part thermostat should change completely.

There is no need to replace it completely, my teacher thinks it is smart to say it, I guess you just need to change the thermostat.

in order to confirm, the thermostat is where I marked it in the photo. Do I need to take the air to be formed in the system after this process (I have investigated this bleeding event, but it is said that the heating pipes have a bleeding place, but I could not see it, obviously) or is it sufficient to run the car until the fan opens with the cover open? I want to clean the cooling system completely when I am already in this business.

If the thermostat is like that in the 206 'minutes, my teacher will take a t-shaped piece on the hose to the heater core. There was an issue with cleaning the cooling system.

thank you for your interest, sir, I will deal with these things at the earliest opportunity.

Friends, I changed the thermostat, the problem disappeared. The temperature gauge that hovers around 60-70 stands around 85-90. We solved this problem, but we still haven't found what the cable does.