No generator output

It shouldn't be difficult. The box contains 2 items, the relay and a delay circuit. From the factory, the connections are pigtails connected to the relay, so wiring it in is a matter of:
o MAKE SURE ALL IS UN-PLUGGED!!
o Did I say "MAKE SURE ALL IS UN-PLUGGED!!"?

o Mounting the box
o opening the appropriate knockouts
o installing cable clamps
o routing the two input lines - one from the generator, one from the shore power connection
o routing the one output line
o wiring all grounds to the ground buss
o connect appropriate wires with wire nuts per instructions printed on the inside of the cover:
1) Generator hot & neutral (black & white)
2) Shore power hot & neutral( black & white)
3) Output hot & neutral (black & white)

The instructions are available on Progressive Dynamics website.

I'll be installing a Marinco bulkhead disconnect at the same time.

Edit: fixed a typo or two...

BruceMc, are those units hard to install?

That's the one I just ordered for our new unit. Hopefully they don't fail often.
I'm planning on mounting ours in a storage compartment with good access.

Well, after some digging, I found the transfer switch. It is buried in a closed in compartment under and behind the wardrobe. I pulled the electrical breaker panel and could see it under there. I ended up cutting out an access under a drawer and finally could reach it.

It is a Progressive Dynamics PD5110nGenerator Transfer Relay http://www.progressivedyn.com/pd5110010.html

I tested shore power and found power coming into the relay and out feeding house 120v. I unplugged shore power and started the generator. Power in, but not out. Its location is a major PIA to get to to change the relay.

Contemplating next steps (meaning beer time...)

I agree, the 2 primary culprits are the breakers on the generator being tripped, even if they don't look tripped, and the possibility of needing to plug the shore cord into the generator's outlet. My 2007 Winnebago has an outlet in the electrical compartment and no transfer switch. One less thing to fail.

X2 on resetting the breakers on the generator.

Like someone else said, your motorhome may not have an automatic transfer switch. Follow your shore power cord. Usually, in the same receptable box where the end of the wire is connected, there is a female plug where you plug in the opposite end of the shore power cord.

There are probably one or two circuit breakers on the generator. Just like in a house, they may look fine but actually they are off line. Flip the breakers all the way off and then back on..Hope this helps.
Also in some older system you actually had to plug the coach into the generator or plug the coach into shore power. Just thinkin.

Is there a shore power receptacle in the generator compartment or in the compartment where the shore power cable stored? Not all Motorhomes use a transfer switch, some you have to plug the shore power cable in.