Voltage on stereo

[bluecorsa]

Recently my car has been cutting out. It's been to Vauxhall and all they've done so far is upgrade ECU software.

It's always when the engine is warming up from cold and only does it sometimes. The battery light always comes up on the display first, then oil light and then the EPS light. I'm suspicious that either the battery or alternator is shafted.

I've been monitoring battery voltage on my headunit over the last few days (Pioneer DEH-P70BT) and been surprised to see it varying between 13.2V and 14V at different times of driving and sometimes when having different equipment switched on in the car (aircon, lights, heated window/mirrors).

Is such a high variation normal?

[Martin]

In older cars when you switch the air con on, you can actually feel the car slow up, and watch the petrol needle drop. althou you should see a peak it running at 14.4v with the caar running and aircon etc off.

[bluecorsa]

Usually it runs at around 13.4 to 14v with the aircon off. Never seen it as high as 14.4v.

[Martin]

hmmm. maybe one for ka$h then.

[B4PJS]

that voltage variation should be fine mate, it needs to be above the 12v of the battery to charge it snd they are reasonable values for different equipment being on/off.

[Martin]

surely it should be running at 14.4v, thats what the vxl 40amp alt produces... according to my voltmeter...

but yea, so long as its above 12, its working

[ROBBORACER]

14 or so volts when mota running is ok but it shouldnt drop too much with any kit on. Get the battery tested with a proper tester that puts it under a load to.