2005 Accord euro alternator issues

Hi, I'm new here so thanks in advance for any help.

My battery died and wouldn't charge, a friend checked the battery and alternator with multimeter and there was no charge coming from alternator. I have replaced the alternator with a brand new non oem one and still battery light stays on and battery is not charging.
I have confirmed the battery is good, and if battery is charged the car has no problems at all until battery dies.

Is there a fuse I can check or some other basic checks I can do before I waste my money on a trip to a mechanic.

My car is a 2005 accord euro 6spd, and I'm in New Zealand, thanks in advance...

Is the ground wire from the negative battery terminal to the car body looks OK and not oxidised?

Yeah it looks good, I played around with that

Forgot to mention that I got the car stuck when this happened, bottomed out pulling off the road in the dark and couldn't see the 10cm drop, car is lowered on adjustable suspension, there is a wire hanging down around the cat , is it possible this causes it, not sure when or where the wire came loose or even if it is from cat

It may...
It could be the oxygen sensor wires and it could be shorted. In saying this, there should be the engine light that turns on
You should check all the fuses, both inside the cabin (esp #15) and the fuse box in the engine compartment (with a multimeter).

How did you go with this?