Astra J (2011) 1.7 Diesel - Poor Battery Charging, Alternator Issue & Voltage Drop to 12.5V

Hello. I have a problem with the 2011 astra J 1.7 diesel car. After firing up, the charging is around 14.8v, but after about a minute it drops gradually to 12.5v. I bought a second alternator and nothing has changed, the problem persists. Where to look for the cause. The charging indicator does not light up.

kisiol wrote:

Hello. I have a problem with the 2011 astra J 1.7 diesel car. After firing up, the charging is around 14.8v, but after about a minute it drops gradually to 12.5v. I bought a second alternator and nothing has changed, the problem persists. Where to look for the cause. The charging indicator does not light up.

Start with the wires that connect the alternator to battery and battery to ground. You absolutely must have it working. It is best to disassemble, clean and assemble.
Cheers!

The masses of the alternator cable have been checked, no changes

Do you have the voltage at the output of the alternator in relation to the rear housing?

Yes there is tension. The alternator charges well immediately after firing, after a while the charging starts to drop.

And have you measured the charging after a longer time, e.g. 4 minutes?

It is 12.5 to 13v max

The Astra J has an "intelligent alternator", ie the charging voltage is controlled by a computer. When the battery is charged, it can lower the charging voltage when stationary to reduce fuel consumption / emissions.

In my previous post "ate" the word "what" came out a stupid question and a stupid answer. Its intelligence (of the alternator) is very easy to check, put more and more load on it and the voltage should increase.
Check the voltage directly on the alternator, then on the clamps and draw the appropriate conclusions.

I read something about this intelligent alternator, except that it is probably not very intelligent. After the car is turned off, the voltage is 12.0v a little bit. After two days of downtime, there is a problem with starting the car, aku. new. Turning on full load, that is, blowing max rear light and air conditioning, still 12.5v.

If there is a problem with firing after such a short time, either you have something wrong with this battery or something is eating it heavily at a standstill.

Current consumption when stationary is 0.07A. So much battery after turning off it has only 12.5v. The second car of the older date is 13.5.v. Aku in working condition I changed 100% with another car.

Check if the glow plugs accidentally do not heat up after firing.

Maybe the problem with the lack of charging in the Astra IV J was solved because I have the same problem? Where to look for the cause?

You solve this problem? This problem like my problem. Maybe bad alternator?

Dodano po 7 [minuty]:

Ay check with Delphi diagnostic F, and l terminal. Under load after start ventilator, rear heater, ksenon light, F terminal load with 100% and voltage go to 13.8 volts. Problem its if F terminal say 100% probably alternator its bad. My problem its in idle voltage go to 12.4, after start headlight voltage go to 13.8. Maybe alternator?

At the ground terminal, the cables for battery charging control are connected. Unplug the plug with them from the clamp and drive a few days and check the results.

Thanks for the tip but after disconnecting the power consumption sensor the following things happen. The charging voltage for the first 3-4 days is around 14.9 -15.1 V. After that it drops to 13.9 V in winter days, and when the ambient temperature rises above 30 C the charging voltage drops to 13.5. Except when the ECU detects a drop in battery voltage and raises the charging voltage to 14.4 V. So if you have this problem when the "smart" battery charging system is not working and you do not have a charging voltage of about 13.8 -14.9 V try disconnecting the power sensor at - battery half and will have and charging voltage (minimum but still operating voltage). When this fault was detected, the consumption sensor was replaced, the alternator was replaced and there was no change. I doubt the body computer but I only doubt it because this problem has taken up enough of my time

>>20065267 @damirbarisichsplit jel si resio problem? Sve iste simptome imam.

>>21581468 Sve sam objasnija u ovom postu iznad. Pažljivo ga procitaj. A Astru sam proda prije 3 godine. Poz.