Garmin GPS MAP 185 ???

[fishinwrench]

I took a boat in on trade that has a pair of Garmin GPS MAP 185 units on it.  I'm Keen on Lowrance and HB units but have never played with any of the Garmin stuff.   There is no card in these units and the GPS puck is missing.  

If I just replace the puck will the gps mapping feature work or do I have to have the card? 

I'd like to have these units operational (for the most part) before putting the boat up for sale.  If they are basically junk don't hesitate to say so, and I'll just install units that I'm more familiar with.

Thanks.