when i put on the a.c. on my 99 tc, the passenger floor seems to get wet. i looked under the car but see nothing, anyone know how this could be fixed?
and what is causing it?

the AC condensor might be leaking into the car. You'll have to find it behind the dash on the passenger side and replace it if it is.

remove the righthand side windsheild trim and inspect for leaves stuck in the case top drain,also remove the fresh air bolts to the top of the firewall and reseal the mateing surface with silicone.

the AC condensor might be leaking into the car. You'll have to find it behind the dash on the passenger side and replace it if it is.
is it outside the car or in the interior.

If the a/c is leaking it will be an oily, real bad smelling gas. The condensor that the air blows across inside the dash accumulates condensation which drips off and usually runs down a hose and out of the fire wall.For what ever reason the condensation is probably running off into your carpet instead of out the drain tube. If it's the heater core leaking, it will be coolant on your carpet.