The doghouse cover is how you access the top of the engine from a Class A motorhome (from the interior, in between the driver and passenger seats)... since the bus style has a flat front and there is no exterior "hood" to open otherwise. Just a swing-down panel to access a few parts of the engine front.
Coil, spark plugs & wires, valve covers, throttle body, etc. are all reachable under the doghouse cover. It sounds like the OP figured his out, but there are usually just 2-3 clamps that can be unlatched and allow the cover to be lifted straight up/off.