Sounds like you have a loose or damaged hose to your heater or perhaps the heater radiator is damaged.
Intake manifold gasket
It leaks from the failed part.
this could be from the heater core. When the heater core goes out it leaks....right into the passenger side floor board If it is water, not coolant, the problem could be a plugged air conditioner drain. Easily accesible from under the hood.
Check coolant leaks with a visual inspection. Clean the engine, then see where the coolant reappears. Look under the water pump. Check engine oil to see if coolant is leaking into the oil.
A coolant additive that seals some external leaks and closes off internal coolant passageways including stopping flow in a radiator or heater core. There are different products for different applications. There is a radiator leak sealer which uses "organic material" to seal leaks, and a head gasket/block sealer that uses sodium silicate to solidify under high temperature.
In the V between the engine blocks and under the plenums.It is a COMMON source of coolant leaks.
The fuse for the fog lights in a 1993 Ford Ranger is located in the fuse box. The fuse box is located under the hood, or under the driver side dash board.
on the passenger side floor board under the carpet
I had the same problem. You can buy harmless dye at an auto shop to put in so you can trace the leak's source.
Sounds like you have a bad heater core. Same thing happened to my car. Had to replace the heater under the dash. Check your coolant lines in and out first for leaks.
From Haynes Manual #36071, 1993-2005 Ford Ranger Pick-ups: Recommended coolant type: 50/50 mixture of Motorcraft Premium Engine Coolant (green colored) or Motorcraft Premium Gold Engine Coolant (yellow colored), or equivalent. The manual does not specify a particular color for a particular model Ranger. You might want to check the label under the hood to see if there is a preference for your vehicle. There are 50/50 mixtures on the market that will mix with either color.
Heater Core or Hose has been compromised? Remove Cover for heater under dashboard if Coolant leaks out Heater core / hose has corroded through Replace Core or Hose. You may need to start car to operating temperature in order to locate leak Be especially careful under dash Once Coolant lines are pressurized ! you may see stream of coolant shooting out of hose or Core ! Eye Protection should be worn !