Astra G 2.2 - Electrical Issues


I have an Astra G 2.2. It was working just fine, no issues. Recently passed MOT with no advisories or issues.

Today I topped up the oil and replaced the overhead interior bulbs with LEDs. They aren’t the “boy-racer” LEDs bought cheaply online. They are basic white LEDs designed and spec’d for the car bought from Halfords. They fitted no problem and worked great, still no issues.

I then took the car out for a drive and for the first 30 minutes things were fine. Then I was driving along and suddenly the red battery light came on and I lost traction control, ABS, powering steering and airbags (the warning lights for all these came on). The car was still running and I managed to drive home, very slowly and carefully.

The interior and exterior lights are still working, although the high beams won’t go on. Radio, wipers and indicators will still come on, but the car won’t start after I turned it off when I got back.

I also have the “Engine Electrical Fault” fault light on now.

I tested the battery with a voltmeter while still connected and the engine running and with the engine not and it clocks in at 9.10V.

I find it coincidental this only happened when I fitted the new LED bulbs in the interior but does anyone have a better idea of what this is?

With the engine not running the battery voltage should be 12.4-12.6.

With the engine running the battery voltage should be 14.3-14.8.

It sounds like the charging system isn’t functioning.

And once the battery voltage drops below 12 volts it’s considered a dead battery. And that won’t start the engine.


My suspicion is that the alternator is failing and it took the battery with it.
The OP should have the alternator output checked immediately, before he kills the replacement battery and winds up stranded and in need of a tow.

+1 for Tester and VDCdriver.

What Is An “Astra G 2.2” And Who’s The Manufacturer ?
Thank You.

Sorry, Just Curious, What’s An “MOT” ?

Check the charging system fuses and make sure the alternator wiring is working right. Besides the 12V line to the battery, there should be a switched 12V, low amp line to the regulator for ignition signal. If this line is not sending battery voltage with the ignition on, the alternator will not charge. After that, have the alternator tested.

‘What Is An “Astra G 2.2” And Who’s The Manufacturer ?
What’s An “MOT” ?’

I believe that the OP is referring to a model of the Vauxhall, which is essentially identical to another GM model that is made with the Opel logo.

“MOT” refers to the Ministry of Transport.

One variant of the Astra has become–more or less–the standard police car in much of the UK, and if you watch any of the detective/police programs on BBC America, you have undoubtedly seen them.
Here is some additional detail:


I was afraid I was having a senior moment, turns out I was just ignorant. I feel better now, somewhat.


CSA Your are not ignorant by any means , you just do not live in the UK . I will add that you do give good advice . The MOT standards appear to be really strict if what I have seen on Wheeler Dealers is correct.