Hi,
I have a 1993 Corsa 1.5TD and the battery warning light decided to pop itself on on Sunday evening just as I was pulling into my drive. Didn't have time to check it out yesterday, but having searched on this NG I carried out the following checks:
1) Checked battery voltage without engine running. Was around 12.7V. So battery okay. Should be as it's less than 1 year old.2) Started engine. At idle the voltage varied between 14V and 14.7V and the engine sounded very "clunky" until it got warmed up. It was like the engine was revving then not revving, hunting I guess you could call it. Haven't noticed that before.
3) Once that had stopped, it settled down to 14.65V at idle with no electrical load.4) Having turned on the lights to full beam, and putting the fan on, it showed about 14.35V at idle.
5) Stopped the engine and the voltage across the battery is around 13.5V.Unfortunately, the leads on the meter I've got aren't long enough to enable me to rev the engine and take a reading.
So, it seems that the alternator is actually charging the battery. The battery seems to be holding a charge and the engione starts okay. Any ideas as to what it could be? If it was the regulator would I expect to see higher volts at higher revs? If it's not the reg/rec then what else could it be?
Thanks, Colin.