Hilux LN105 weird charging behavior

[svandore10]

Hi, I have this weird issue with charging, when engine is cold it gives 14.4 V but gradually as engine warms up it drops to 13.2-13.5. I already checked external regulator and measured ohms which looks good. I think there is bad electrical connection somewhere, where should I check? Of course battery terminals and terminals on alternator itself but are there some another which I can check also?
Thank you for your answers

 

[gnob]

on my 106 the alt has a small pigtail that connects to a ten pin near the battery. mine was roached from acid and wear.