And you will need to ensure you understand all the connections on your car's loom, and where they should connect (or not) to the empeg sled. Might sound silly, but there is a lot that can go wrong at this point.

Questions -

Does it boot in the car?
Does the amp power on?

If both of the answers are yes, and you have followed JBjorgen's advice, then you may need to get into checking connections, cables, polarities etc etc