ENGINE STARTING PROBLEM BATTERY / ALTERNATOR

[az_e11]

I went out today to fit in a digi dash in my Nova, took me a while, any way, as it got dark i had to use the courtesy light in my car, i left the light switched on for a while, while i was fitting the dash.
Once i had finished fitting the dash, went to start my car, sounded weak at first, then it suddently fired.
Went for a long drive, and then i switched my car off, went to restart but battery was dead, so i had to jump start it, on the way home my digi dash , headlights were getting dimmer and dimmer until had i had no power on the dash or anything, no power in anything couldnt even indicate or listen to music, engine was still running though.

This is weird coz, even if i did leave the courtesy light on for a bit, shorly the battery should have recharged itself while i was driving(went for at least an hour).

I was thinking maybe the battery can no longer hold a charge, but surely while the engine is running there should be enough power for things in the car, including lights dash and everythig else.

PLEASE HELP!!!!
Could this be a dead battery now, or a faulty alteranator, coz i av double checked my my digi dash wiring nothing wrong wit that.
I might just replace the battery dunno

Thanks

:?

[robb]

Get a multimeter and set it to read volts DC, put it between the battery neg and the big wire on alternator, if it reads anything below 13v the alternator is knackered, remember it may not actually charge on tickover, rev it a bit when you test it.
Also you can check the battery this way, it will slowly discharge (1/10th volt per 5-10sec) if there is no charge from alternator.

[Philsutton]

stupid question but is your alternator belt is still on?

[robb]

Or tight lol

Digi dash has a bettery meter too, this should read 15v when the car is running (above 1500rpm IIRC).