For the past week or so, I've been hearing the sound of sloshing water in the cab of my truck. Ruled out the step-bars and doors, and traced the sound to the A/C equipment under the passenger dash. I took the plastic pan off thinking it was holding water for some reason, but it isn't. Apparently, the water is inside the condenser unit there. Has anyone experienced this before, and should I be afraid to go ahead and take that box off to get the water out?

 

Hi and welcome to FTE.
You could have a stopped up drain. You could try blowing some compressed air into the drain on the outside of the firewall and see if any water comes out.
Jimmy

 

I am not sure if this is your problem but I had the same problem on my wifes chevy blazer and my daughters jeep grand cherokee. The problem which was easily corrected was air in the coolant system at the heater core. What I had to do was disconnect the heater hose going into the firewall and pour antifreeze into it until it ran out. After hooking the hose back up the problem was gone! Hope this helps.

 

make sure your coolant is topped off