Wayne,
I have an 04, but I think they are probably the same. The slide out circuit and relays are located in the battery compartment inside the solar control panel. This box is mounted on the left side of the back wall of the compartment above the batteries. There should be a label on the box indicating that the slide out circuit is inside, but it is just paper and could be missing. I've had to glue mine back in place.
This is a good starting point. You can swap a couple of the relays to see if it is the relay. Either way, this is your starting point for troubleshooting.
Good luck,
Bill