I just ordered the parts to replace the relays to prevent problems (no known issue) - I have 3 OMRON relays in my fuse box (same as picture in first post) - should I replace all 3 or just the 2 marked? The DIY linked suggests only the fan relays, not sure what the 3rd relay above is.

Any thoughts?

Thoughts
 

My thoughts....I replaced the two that control the cooling fans, because I had a problem with overheating and it solved my problem.

These relays are probably pretty common in the car.

If you want to take the time to research the function of the relay you're referring to, then decide for yourself if you want to replace it now or just be aware of it in case it fails.

I misplaced my manual.

Can anyone confirm the drivers side fan should come on before the pass side fan and run just as hard as the ac fan? My car began to get hot sitting with a.c. on and it threw a lean code.

Disregard. Bought and replaced, found one relay dead. I'm going to cut it open, I'll see about posting some pics for you guys.

'04 owner here(199k), just replaced the omron relays with the "~5" good relays, wondering if there's any need to replace the "fan control relay" as seen in OP's diagram, the smaller box just to the left of the main relay box. It's also an omron and I'm thinking it has the same faults.

After replacing the two relays as suggested in this thread my fans did indeed start running as normal (with the exception of the ac condenser fan which is another problem I've still gotta diagnose).