EK9: Electrical gremlins, part 1: The Battery

Lately my car is having some electrical issues. The bad thing: Electrical issues on a car are most probably the most complicated ones to find. The good thing is I’m electronic engineer in a service department, so looking for broken down circuits is kind of my thing since many years 😀
I had three major problems:
– The car would not start anymore after leaving the car off the battery charger for only a few days.
– The brake-lights don’t work anymore (sometimes they do after a long drive work, tho)
– The left low-beam headlight doesn’t work (even after exchanging the bulb)

The first issue was solved during the last days.
It used to start great a few days befor i left the car in the garage without connecting it to the battery charger and suddenly nothing happened when the key turned. The battery was flat. However i wondered what could cause this and so i measured if something would drain the battery. but a current of somewhat 6mA (DC) shows that there is no leaking current when the car is parked.

So the only possible answer is, that i somehow must have left the headlight switch on or something else that flattened the battery during these days. Or it just was old. Since i not drive the car daily i guess the battery is easy to stress after staying in the garage for a long winter. even when hooked to the battery charger.

I was afraid since this (a bit special sized) battery was quite expensive last time (250 bucks or so). But a bit of googling revelaed that https://swissbatt24.ch/ would supply it within two working days for only 97.- CHF. great deal and great service! It even came with a free bag of battery connecting terminal lube.

Replaced the battery and car starts and runs again as it should.
Will adress the other two problems later.  have to investigate a bit first, but at least i can drive her around again 😀
Currently i’m guessing that the Brake-light switch might be broken and that some connector / wire problem is causing the low beam left to stay dark.  we’ll see 🙂