On my 98 Blazer 4x4, I have decided that whoever had it before & changed the heater core & messed with the housing by cutting out the access to the fan motor etc. Have done something to the drain causing water to set in the case. At one point I had a bunch of mixed water & antifreeze pour out. Now I can briefly smell moisture when it gets up to temp. It will fog up the windows until the moisture is gone then clears up. The truck doesn't loose any antifreeze. I'm sure it is a drain issue because we are still running A/C every day here.
My question is does anyone have a diagram of the case & were the A/C Evap & heater core are located in the case.
I want to just drill a small hole at the lowest point & drain the case & see what comes out.
Unless someone has a better idea that is less work. I'm not going to remove the case or get crazy over fixing or finding out why the drain isn't working correct.
Any ideas or thoughts would be appreciated. The big thing is I don't want to DRILL INTO THE EVAP or ANYTHING THAT WILL CAUSE AN ISSUE I DON"T ALREADY HAVE.
Thanks.

 

No one has been into the Heater A/C housing? Or has any suggestions?

 

well if it were just water and not coolant then id say the drain box fo the ac was clogged with debri. the drain hose i think is located on the passenger side. if you open the hood and look down at the ground on the passenger side there should be a half inch hose pointing down. thats your ac moisture drain. just take some compressed air and a rag to hold the pressure inside that hose and shoot the air into the hose . that will usually unclog it for a little while. either that or they prolly cracked it or busted it up since its only plastic.

 

I can't find any hose. Someone screwed this case up. That is why I was wondering about just drilling a hole at the lowest point I can without drilling into any vital parts. Once I parked on a down hill sideways & got most of the antifreeze that was left in the case out from when a heater core was replaced. It came from somewhere in the frame side, but didn't come out like it was pouring out a hose. What I have now is A/C moisture. I use to smell antifreeze until the side hill deal now just water. So the A/C is not draining for sure.
Thanks for your response.

 

there is no hose for the drain, the drain is a rectangular hole in the box located just above the frame rail.

 

OK. Is this hole the lowest point in the case? or could water/coolant go below it?
Thanks for you response.