Repaired my radiator on 1987 Dodge 600 series, but radiator fan will not go on automatically. When directly connected to the battery, fan works just fine, but not otherwise. Changed thermoswitch twice, and put in new thermostat. Fan still won't kick over automatically. Any suggestions?

I have a 2001 Ford Escort with the dohc "Zetec" engine and about 53,000 miles. For several months and on an intermittent basis I have been finding a small deposit of watery liquid under the engine after the car cools. The liquid is clear, odorless, slightly slippery, and although it doesn't smell like coolant it has a similar taste. A few months back while I was still using the a/c I attributed it to condensation, but the problem continues when the a/c is not used. The puddle accumulates under the catalytic convertor. The first possibility that popped in my mind was a coolant leak somewhere that was running down the block.I have put the car up on jackstands and failed to see any evidence of a leak. Finally last week I spotted a tiny amount of coolant escaping from one heater hose where it clamps to the thermostat housing, coolant seemed to be accumulating on top of the transmission bellhousing and probably running down to the ground. I took the car to a local repair shop where they pressure tested the coolant system, confirmed the leak, and replaced the factory spring clamp on the heater hose with a screw clamp. I have checked around the new clamp for the past 5 days and that leak has been eliminated. This morning although there is no sign of a leak at the new clamp the puddle reappeared on the ground. Could the leak be coming from the catalytic convertor? If it is some form of condensation building up in the convertor as it cools, what does it signify? If a faulty emission system is it still under warranty (I live in California)? I thank you in advance for your advice.