Hi guys
Second "breakdown" this morning due to flat battery after turning the car off. I filled up petrol on the way to work.

My gen warning light won't go off and I thought it might have been a bad earth. On the weekend I took off my earth strap and thoroughly cleaned the connection. Both to the car and to the battery. I made sue there was a gearbox earth strap and generator earth. All to no avail.
I don't own a multi meter and plan to buy today to see hopefully where the issue is. But I have a new 75Amp alternator sitting at home. Do in just rip the generator out and replace or so you think I need to solve this issue first. My thoughts are that the generator isn't charging or I have wired something incorrectly.

This is my first real driving period since buying the car 4 years ago and I can't remember if the warning light was on bAck then?