By the time my father left my mother for another woman, I was twenty-four, but already psychologically damaged for life by my upbringing.
I thought many times of contacting him and looking for some sort of explanation, or to understand him now that I was a father as well, but I never did, so maybe deep down I didn't really want to.
When he died, he left instructions that my two sisters, my mum and I were not to be notified of his death until after his cremation - I don;t know if he imagined we would all turn up to weep / dance on his grave.
I don't regret my inaction, I am OK to go forward and deal with my demons, sure that it wouldn't have helped to try and see what made himn the way he was.
I can only say - think of your dad as dying tomorrow. Would you regret not having seen and talked to him? I don't - you might.. Put yourself in the situation, look at your heart's reaction, and go ahead with what it tells you.
Listen to everyone's advice, take none except your own.