As far as I know, Bill is correct: you are dealing with only circuit breakers, not fuses. But because you have both brakes and signals out, it could be a faulty or wet relay. Make sure one of your tail lamp modules doesn't have a shorted wire or connection.
On my '06 Monterey, one relay controls both, relay #K18. In my chassis electrical bay, K18 is on the far left of the second row up of relays from the bottom (5 rows total on mine). Yours may be a different number relay in another position, because it's an '04 model; find and follow the white wires with brake lights and/or turn signals stamped on them - where both hit a relay, that's the one. I say a "wet" relay because if water seeps into that bay, as it has mine, moisture could infiltrate, corrode, and foul any electric component or connection. I now keep a dessicant (Dri-Z-Air) unit in that bay, and have used Corrosion-X and dielectric grease on exposed connections and inside connectors. Heaven help the circuit board boxes mounted in there.
Check that your wire connections on Terminal Bus' 1 and 2 are tight, esp. #2, #3, and #7 on TB1, which on mine are left and right signals and brake lights, respectively. Check also your related circuit breaker connections for tightness, which on mine are CB36, 2nd from bottom on my left circuit breaker bar (turn signals) and CB7, 7th from the top of the middle bar.
That all said, it could be something else, but that relay would be the first thing I'd consider checking, and it's doubtful two circuit breakers would go at once. Besides, those 2 circuit breakers control other devices, including ignition relays (does the coach start?) and parking lights, so if they are out then maybe it is the breakers. The relay controls only the brake and signal circuits together: prime suspect.
Joel
