I have a 1996 Dodge Ram 1500 pickup V8 auto transmission... recently I have noticed that my floorboard is soaked, especially on the passenger side... A friend of mine told me that it could be a heating coil. Just wanted clarification before I take it to a mechanic...

Take a wire (or long pipe cleaner) and insert it into the A/C evaporator coil drain. Condensate is backing up and emptying on the passenger side of your truck.

While you are at it, you may want to perform this step:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-7.html#post1207763

Don't know where heater core is on dodge trucks but my grand am had same problem.heater core was fine but the pipes going threw the fire wall were plastic and broke.new heater core had metal pipes.