Hiya, I've been taking a look at this Club Forum for a couple of weeks now (just got a 2001 1.6 SXi after getting my 1 yrs NCB!) and I thought I'd join to get some help.
It looks like a common fault with the Astras are the emissions lights on the dashboard.
Mine has been lit up for the past 2 weeks (but very dimly so I can only see it @ night ) and I took it to a local garage today who hooked it up to the machine and read the ECU - the only fault code registered was "A/C Low Voltage" or something similar.
They reset the ECU, took my £30 and told me to be on my way! Right now it's turned off - but what should I do if it turns back on