changing airlines at SJU
 

I'm trying to put together a flight to Grenada that would require changing airlines in SJU (Delta to AA or Continental to AA). Orbitz keeps returning a combination that shows a 65 minute layover, then notes a "change in terminal". I've been through SJU many times but have always been on AA so don't have anything to compare this to but it doesn't feel very comfortable to me. Any feedback is greatly appreciated.

I don't think you'll have a problem unless your plane is really late.

The San Juan Terminal is in one building. Changing from Delta to AA (you may be going American Eagle) will require a long walk but you have plenty of time unless you can only check bags to San Juan and have to reclaim and recheck.
The problem is coming back since you have to deplane, go to immigration, customs, and recheck bags. You need 1.5 hrs to do this with ease.

The John C is correct - changing terminals in SJU is nothing to be concerned about. SJU is is one big building with three different "wings" designated Terminals B, C & D. Terminal A is a seperate building used for charter flights and private aircraft. If I'm not mistaken Delta flights arrive in Terminal B at gates numbered in the high 30's (the flight from Atlanta usually comes in at Gate 39). To put things in perspective American Eagle flights use Terminal D, Gates 1 and 2, American Airlines uses Terminal A, Gates 3 through 18 (or 19). All other airlines use either Terminal C or B, Gates 19 (or 20) through gate 40 (why Gate #1 is in Terminal D and Gate #40 is in Terminal A is a mystery known only to the airport designer).

FYI - walking at a normal pace it takes less than 15 minutes to walk from Gate 39 to Gate 1 which is where the Gate for your American Eagle flight will depart (you are probably flying American Eagle not actually American Airlines).

When walking between "Terminal" areas be sure to follow the signs so you stay inside the securred area otherwise you will be directed into the main terminal and will have to clear security to re-enter the gate area. You will have to do this if you have checked luggage that has not been checked through to your final destination. If this is the case you will proceed to the baggage claim area to get your luggage and you will have to re-check it at the ticket counter for your out-bound airline.