Which of several or’d-together subjects should the verb agree with? [duplicate]
Though this is apparently a duplicate of this question answered by tchrist, I figure I should just give OP a response in case he or she feels the need to accept an answer:
The correct way to say it is
Neither you nor I am .....
The same rule applies to "or". The one before the verb determines if it is singular or plural.
[And as suggested by Kristina, Neither of us is to blame is indeed a better way to express it.]
When you are not certain if certain expression is grammatically correct, you can always check with CoCA.