Okay. Don't worry about fuse numbers and wire colours changing between model years, manufacturers do that all the time and Volvo is no more guilty than most. The way the wires run will hardly change between years though, so you can easily identify what is running to where by resting for continuity/discontinuity.
The fuse numbering on the back of your fuse box is almost certainly right for your car, so use that to identify what goes where - there will be a 1:1 correlation (more or less) with the cct diagram on pp 96 of the wiring diagrams:
Let's be more methodical and see if we can find the fault.
First of all let's think about the warning buzzer that someone told you to change: this operates under the following conditions:
a. keys in/door open.
b. Lights on/door open.
c. Keys left in car.
... so the first thing to do it check it works under these
- none of these are anything to do with the fault you have reported, so we may almost certainly discount the buzzer relay.
So, the problem almost certainly isn't with the warning buzzer cct, it is with the hazard flashers cct. Someone (Bob I think) mentioned that the seat belt warning should slow down when the hazards are turned on - this is probably because they share a common power supply from fuse 13 (it might have a different number on your car, but it will be easy to work out what that is), so they interfere with each other. Don't worry about that.
Again thinking methodically, do the left and right side indicators work normally? If they do then the indicator relay is okay (all it does is turn on and off, it doesn't matter which cct that is for). If the left and right indicators don't work properly then change just that relay and the problem will probably be fixed.
So, assuming the left and right indicators work properly, what else is left to be faulty: either the hazard switch (someone, I think Bob talked about this - the switch will be easy enough to check electrically - it only does one thing - off and on), or there is some wiring between that is playing up (maybe chaffed through to earth on the body).
Once you have checked the switch for continuity/discontinuity and either fixed it or discounted it, the only thing left is those bits of wire. There are only 6 of them (look at the diagram I've left you above) - you can probably discount the bottom 4 if the left and right turn signals work properly, which leaves the two power cables at the top - if I were a betting man (which I am not) I'd go for the one that is common to the warning buzzer fuse (I think I said this several posts ago). Checking each wire for continuity/discontinuity and to earth should tell you what is wrong if one of the other things I mentioned in the process has not already led you there.
All this is just logic - nothing to do with owning Volvos for 50 years (which I have not) or being a member of the VOC or this forum since Abraham was a boy. My only relevant qualifications in this respect are that I'm an electrician, have been fixing cars and bikes for decades and have a degree in physics. I will not be offended in any way if you want to ignore all the above and just randomly change bits to see if they work, but I have spent long enough on this problem.
I hope you fix your car.
Alan