2005 mercury 40 hp efi delayed ignition power

I just got the motor back from shop for impeller and oil changes. Tried to start it for the first time since then to winterize it. It acted like the kill switch was thrown or that the battery was disconnected. I checked it all out and all seemed OK. Checked fuses wiring etc.. So odd thing happens. I am putting the shroud back on and the key is still in on position still. The ignition horn finally beeps and she starts right up. Purs like a kitten. There is a long delay before the horn will beep. Maybe 5 minutes is what it seems like, for the horn to beep the single ready to start beep. What the heck does that mean? Any ideas? I don't find it on the list of codes. It does not seem to indicate a bad sensor or anything from the codes.

Bad Ignition switch.

..................or a loose connection or a partially broken wire, or a corroded terminal, or a delay fault in the PCM, or about a 1/2 dozen other things. You said that when you put the cowl on, the ignition activated: that's where i would start looking. Look for pinched or bent wires, corrosion, etc.

Thanks much, will try to let everyone know how it goes.