Agree with the others here.... just walk it. I forgot that the last time I tried to walk it the sidewalk was closed due to construction, but that was years ago. Others are reporting it clear now.
The two terminals are adjacent to each other but the drive between them seems like miles.
Something else to remember.... when you get to T1 check the monitors to find out which gate you use. This seems obvious, but if you just follow everyone through the security checkpoint right after the baggage claim area you may have an unpleasant surprise.
WN has two sterile areas at SAN. Gates 1-2 are at the far end of the terminal past the ticket counters and have their own checkpoint. Gates 3 - 8(??) are closer to the center of the terminal and have their own checkpoint.
Oddly I've flown into gates 1/2 plenty of times, but have never flown out of them. I'm going to kick myself when I don't check the monitors and end up waiting in line at the wrong checkpoint.