Seat heaters diagnosis?????

[BriceW at webtv.net]

Last year all of the seat heaters worked great on both front seats and
both rear seats.
Now only the passenger front seat works just a little. It hardly gets
warm at all and I have the switch all the way on 6 and you can barely
feel it.
The drivers seat and both the rear seats do not work at all.
I installed brand new switches(which is nice to have them lit) and
installed 2 new relays. No change in anything.
The fuse is good.
Could it be the ground wire from the fuse box to the relays has a break?
The rear seats work off of pressure switches and I doubt that both would
go bad.
What do the 2 small silver circuit breakers do that are to the left of
the seat heater relays on top row 1 at the very left?