90Q charging system issues - three control lights faintly on

[Joshua van Tol]

The slightly glowing idiot lights usually indicate a failed diode in the alternator. If you have a multi-meter with an AC volts setting, put that on the battery while the car is running, and see what sort of AC voltage you've got. If it's more than a couple hundred milli-volts, it's probably a shorted diode. This will often also cause the battery to discharge while the car is off.


On May 22, 2011, at 11:21 AM, radek at istar.ca wrote:

> Tried to drive my son's car this morning and voilà:  three idiot lights light up very slightly when the car is started:  charging, handbrake and brake pad usage (looks like two drum brake pads with an exclamation sign in the middle, I didn't know 90Q had a provision for brake pad usage light).  Voltage on centre console showing below 12V.
> 
> Where to start:  instrument cluster, the trunk (no reverse light and no plate light, wires must be broken)?  I wonder if a short somewhere would prevent the alternator from charging fully, in other words, would the drain take all of alternator's power?
> 
> Car got a brand new alternator a year ago.
> TIA.
> Radek.
> 
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