I'm not sure of the correct use of "was" or "were in the following sentence:

I checked the doors and neither of them (were or was) locked.
'neither of them' means not one of them. It is invariably singular: was.
neither one was.
Try out our live chat room.
were locked... was is singular and were is plural.

I checked the door and it was locked.
I checked the doors and they were locked.