My 2 year old son is having a difficult time falling asleep for his daily nap, which was previously not an issue. He had been napping from about 11:45-1:45, but now he fights it desperately and won't fall asleep. I was thinking that it might help if we tried to nap later in the afternoon, but I'm worried that this will make going to bed at night (which is currently not a problem) an issue. Any suggestions?
There is no hard and fast rule on this - all babies are different. With all three of mine, they would have a mid to late afternoon nap at that age and still went down at their usual bedtime, which was around 7pm for the girls (my son wanted and needed far less sleep than them, so had a bed time closer to midnight)
I'd suggest in your case that if he is currently too awake to nap at 11:45 try moving his nap time to half an hour or an hour later and see if he goes down more easily.
It depends on each kid also how far they slept well last night. Sometimes my toddler(21months) sleep bit late at night and wakes up around 7am and he wants a nap at 11am. If he is able to nap for 2-3hours at stretch, he doesn't need second nap. If he slept well last night, he takes one nap from 1PM to 3/4PM. The only thing I make sure he doesn't get fussy in day time especially during meals(he rejects meal if he feels tired). So I adjust it accordingly. I am sure his routine will change again in 3months because he is growing and he may have different demands.