99 GTP - Starting Problem

Problem 1 - When you go to start the car, the battery is dead. Sounds simple, jump the battery, should be fine. This is every time I need to start the car though. Had the battery tested and alternator tested and they are both fine. Checked the wiring and everything seems to be connected and there is no corrosion. As soon as you turn the car off it will not start again with out jumping the battery. Left the battery on the charger all night and still get the same thing. Battery dies as soon as the car is shut off. Any Ideas?

Problem 2 -When running the AC water leaks onto the passenger side floor boards. A lot of water!!! Started soon after bottoming the car out on a gravel road. Taken into the dealership and they said they fixed it twice. Any ideas on how I can fix this for good?

Sounds like a weak battery or poor connections. I would have a mechanic with a vat40 give the battery a good load test. Them little pittily ones auto parts stores use can never load down a battery like a vat 40.

You have checked the battery cables for corrosion, right?

Thanks! I had a feeling it still had something to do with the battery. And yes I did check the terminals for corrosion.

Problem #2
I had the same problem last year. The AC suit case filled up with water and started to leak out of the blower motor. My passenger side floor board looked like an ocean. The drain plug on the AC suit case was plugged. I jacked the car up and found a black rubber nipple on the AC suit case. You'll need a flash light to find it. I took mine off and about 1 gallon of water came out. I never had any more problems with water. I had to replace the blower motor because the water damaged the bearing in the blower motor

All the HVAC drain hose does is allow condensation from the A/C evaporator core to drain out and allow any water that may accumulate or come in via the HVAC intake to drain out especially after raining. The source of the water intrusion is normally the intake cowling seals or poorly designed water diversion channels in the same area. The other issue is '97-'03 Grand Prixs do not have cabin air filter stock. The owner has to install one which is a good long term fix. A cabin air filter will reduce or eliminate water intrusion especially when operating in the normal A/C modes where air is drawn in via the HVAC intake.