2008 Tacoma. Heater box drain??

So I've recently noticed the vent tube from my heater box, pictured here:

Has been leaking a significant amount of water. I would generally assume a cracked heater core would be the cause of this, but it doesn't look or taste like coolant. And my coolant level seems fine. (Neither the A/C nor the defroster have been on, and the a/c compressor is not running) which would lead me to believe that this isn't condensation from the a/c. Maybe this is normal for this time of year, but I didn't notice it last year, or with any other vehicles I've had.

 

You say you're AC or Defrost is not on, but it has to be on (maybe a broken switch?).... Unplug the AC fuse and monitor the underside again, it should be dry after that.

 

A/c compressor isn't running. And I I could be wrong but I believe, generally speaking, the majority of condensation comes of of the accumulator when the a/c is running. Or at least something mounted under the hood, not inside the heater box. Once again I could be mistaken with this.

 

I'd say if it ain't sweet to taste and ain't pink then it ain't coolant. I'd try and collect a bit in a container to verify color

 

The wet spot is directly below the condensate tube from the evaporator. If you say the wetness is not antifreeze, then it has to be water.... ie, your AC is on.

 

Ok, I will check by pulling the fuse, like stated above. Thanks for the input.

 

If I am correct, I believe that when the defrost runs, it automatically turns the AC on and shuts off recirc mode.

If there is water coming from your drip tube when you are running the defrost then you are fine.

In your case where you are not running either it could be a case of condensation, but since that puddle is rather large, I suspect you may either have a clog in your drain tube or something weird. As a previous poster said grab some kind of tub or bottle and collect a sample to confirm if it is water or coolant. The results will give you the answer you are looking for.

 

When the AC runs the majority of condensation is on the evaporator, in the box under the dash. The heater core itself should never leak or condense anything. Condensation is caused by warmer moist air in contact with a cold surface.

The 'box' you refer to also intakes outside air via the cowl vent. It's fairly common for rainwater to enter that and exit via the condensate tube.

Also, a clogged condensate tube (leaves, needles, etc that have worked in via the cowl) can restrict drainage, and allow any trapped water to dribble out over time instead of just flowing out as it should .

 

If the core is leaking your window will fog over the AC comes on, on defrost like it or not it does not matter if the rec. is on or off.

 

Nice. good info guys, I'll look more into it this week. I park under trees at home with both leaves and needles. So that very may well be it.