I have Ford Focus MK1, with 1,8 Tdci engine, and smart generator. Three or four month before this, I have a charging problem, beacuse the battery voltage goes down, the car is stopped, but the battery check lamp (sorry, I don't know, what is the good word for this lamp) didn't show that. The problem was the short bronze brush and the and the ring what connect to this. We changed the complete voltage regulator and the ring.
After that the car was OK for 1-2 weeks, but sometimes the charging check lamp shows, something wrong in the system. If the lapm is on, the system voltage is 14.1-14,3 V. I thied a lot of thing, and I find what happens when the lamp switch on. When I use a lot of electrical system, like lamps, fog laps, window heating, air conditioning, radio, etc.. the battery voltage goes down and the battery check lamp switch on.
I tried to measure with the pico, what happens in the charging system, but I don't know:
I do it good or not, and what I see on the screen????
If somebody knows the answer to my questions, please write it.
Channel A: (blue line on pictures) The blue cable on the voltage regulator connector
Channel B: (red line on pictures) The grey cable on the voltage regulator connector
Channel C: (green line on the pictures) Battery voltage
Channel D: (brown line on the pictures) Alternator current
The measures on the pico are selected between vertical cursors.
I cut off three picture of the measure file, because this is very big.
On the first picture the car is working on idle, and I don't use electrican systems.
After that I switched on everything, what I can. Lamps, fog lamps, window heaters, air conditioning, etc...
The system voltage goes down, the current goes up.
When the alternator is working under big load 2 or 3 sec, the check lamp switch on, but the voltage is grow up for "normal level" (14,3-14,4V)
I have some questions abuot my measurement:
1. Channel A and channel B is PWM sign or "message" between alternator and ECU?
2. Is this a possible solution to change the voltage regulator?
3. When the lamp come on, why grow up the system voltage?
Thanks to read my writing. I hope you understand my problem and somebody can help me.
Have a nice day!