[wambus]

I have a '99 Grand caravan. Shortly after purchase, we experienced the problem where the drain from the AC became crimped (or something). The air box or whatever in behind the dash apparently remined wet for long enough to get moldy. Dealership 'cleaned' it and gave it back. Now I need to 'clean' it every year (or more often if it is really damp). This consists mostly of pouring bleach water down the cowl vents and hoping for the best.

Is there a better solution? My wife called me today to bitch that it was 29 degrees and she could not operate the heat because my asthmatic daughter would have issues. I want to put this one to bed straight away. What do I need to do? do I need to take apart the system? What do I take apart? How do I do it? Whare is the mold, anyway; why doesn't the bleach kill it for good?

Please help....

 

[Bob Lincoln]

Mold will have grown on the fins of the A/C condenser, and probably the fins of the heater core, too. The only way to really eliminate it is to tear the dash apart to open up the airbox. I'd spray disinfectants into the air vents and in the condensate drain each month and see if that mitigates it.

 

[A.j. Schreiber]

I'd take the fan motor out and look on the fan blades as well as into the ducting itself to see if there's any nastiness. Probably wouldnt hurt to give it a blast of disinfecting cleaner and wipe it down. You can access the fan motor by removing the 3 or 4 - 7mm (or 8) bolts/screws on the bottom side of the air ducting underneath and behind the glove box. Another way is to take the engine cowl/whipper housing of and take a look around in that area, again, cleaning it as well. TO do that you need to remove the whipper arms using a 15mm socket as well as the 5 or 6 star bits (T20 I wanna say) and then the two phillips head lock down hinges near where the whipper arms connect, with the top removes you should be able to look inside the ducting with a flash light to check for and crud.

 

[Durang-goer]

Sorry Bob, but the condensor is outside the car, you must mean the evaporator core ?

Wambus, there is a drain for the A/C that usually gets clogged routinely due to it's retarded flat nipple design. It will most likely have a 90 degree rubber elbow kinda like the one on this Durango at the link below, see the pinched end....?..

http://dodgeforum.com/forum/1st-gen-durango/214259-ac-evaporator-drain.html

They are designed to keep water and fumes out, but usually do just the opposite,gagging the occupents in a sauna. Just find it, most are on the passenger side firewall outside, somewhere below where the heater hoses go into the cabin of ur van. Just pull it off, ( I chuck them out ), they are nothing but trouble. Once its off run a piece of mechanics wire through the hole and get rid of any blockage,water sometimes runs out, compressed air works ideal also. You can get some frigi-fresh from BG, ( great stuff ). You can usually get it at NAPA, and it works fantastic spray it in the vents & evaporator hole.

Now one other possibility is a leaking heater core,they will smell funky and kinda sweet like too, are you sure that's not antifreeze your smelling in the cabin, any wet greasy feeling spots on the passenger or center floor ? People usually won't notice it much till they really start depending on the heat. Are your inside windows getting moist or hazed?

Hope this helps point u in the right direction !

 

[Durang-goer]

PS:

Wambus, you might want to re-think ripping anything apart yet,other than drain tube, an evaporator is a huge job. i've done many of these in the radiator shop i worked at in PA. Take a look at these photo's on the link below....oh, and try not to cry too much... :scared:

The dash needs to be ripped right out, this is whats involved in replacing an AC evaporator on a 1996-2000 Dodge Grand Caravan..


http://dodgeforum.com/forum/dodge-caravan/195415-ac-evaporator-repair-instructions-with-pictures.html

Hang in there man !

 

[Durang-goer]

Oh, and the heater core isn't near as bad. It's in the center behind the radio area, to the right of drivers feet, You still will need to pull the wheel out to make room, but not nearly as bad. You should pull the cover off the heater tubes and see if its all green n slimy,
check this vid of a 2000..

http://www.youtube.com/watch?v=wkipjwb7uvY

 

[ImperialCrown]

You can unhinge the glovebox by unhooking the teathers and swing it down. On the black plastic HVAC housing, you will see a large square rubber grommet with a 3-wire connector on it. Disconnect this plug and gently remove the soft rubber grommet. Behind it is the evaporator temperature probe and it is fragile. Be careful not to tug on yank on the wire inside the housing and let the grommet rest out of the way. Leave the probe in the evaporator alone for now. Use this hole to peer inside.
You can visually inspect the evaporator (looks like a small aluminum radiator) from this hole and I imagine that the evaporator won't look pretty. Leaves and other tree debris gets trapped here and with the condensation this can become a rotting fungus and algae farm! This will eat the aluminum evaporator and it will eventually leak refrigerant and refrigerant (PAG) oil. The PAG oil has a strong musty odor itself. It carries a green dye to help locate leaks. If you see green, replace the evaporator. Many Chrysler evaporator kits included a new finer mesh cowl screen to help filter the trash out.
You can treat it with deodorizers and fungicides at first, but that is only temporary. The only real fix if it is leaking is an evaporator replacement. This was a very common service at the dealer. In fact the evaporator warranty was extended to 7/70 in many cars. This has since expired.
The A/C will need special equipment to reclaim, evacuate (vacuum) and recharge the system. It is an expensive service. The evaporator (recommend OEM only) and labor is pricy.
Is the rest of the van worth several hundred to a thousand dollars for a working HVAC system? I would say go ahead if the van has a few more years left in it.

 

[wambus]

Thanks for all the advice. I will investigate further when the temp climbs a bit. I poured bleach down in there last night and rinsed to beat the band.
I have not noticed the smell of anti-freeze, but there was the impression of water evaporation on the windshield above the defroster vents. I was thinking it may have become plugged again and was actually holding water. When I filled it, though, water was running out below. Maybe it was OVERFLOWING... not sure. As for the AC system leaking, how long could a leak exist before all the freon was gone? The funky smell has been around a really long time. Mostly evident when first starting up the AC. Usually goes away fairly quickly...

This drain thing sounds just like my Passat. VWs have a stupid sunrrof drain thing with the pinched outlet. Supposed to prevent bugs from getting in and stopping it up. Low and behold, they just stick and do the stoppin up all by themselves....

 

[Durang-goer]

wambus,

You really shouldn't be dumping any liquid down that dash vents, and definately not bleach as it's extremely corrosive in nature. Plus all that liqud will only add to your dilema. Why not just start with your outside case drain tube, the pull the bolts & cover off the heater core to take a look?

And when we talk of the A/C system leaking what we mean to imply, is the water condensing ( off the Evap ) inside the heater case, that is supposed to drain out the drain tube under the hood. ( where it drips onto the ground ) if that tube is blocked at all, even partially, it will hold the water inside the case.

And I agree totally with ImperialCrown, sprays and deoderizers are only a temporary bandaid to mask the real issue. But, then again, nobody to my knowlege has really yet implied you need an evaporator core, we need to address the moisture issue 1st...and thats never going to happen until you quit dumping water & bleach in there. Moisture is the real issue here, mold & fungi can't grow without moisture. And when you dump liquid into the case, it most likely isn't even coming near the Evap, just adding to the moisture problem.

 

[ImperialCrown]

Agree. Bleach is very caustic and will react with the aluminum that the evaporator and heater core are made of. The bleach odor may also be unpleasant for the occupants.
When you get to actually look at the evaporator coil through the probe access hole, you may see lots of tree debris that has been ingested over the years. This debris will sit there and rot. It will also destroy the evaporator and eventually cause it to leak refrigerant. Part of the odor problem may be leaking PAG oil. The refrigerant itself really doesn't have an odor, but isn't good to breathe.
Chrysler has TSB's for treating evaporator odors, although in many cases it was only a temporary fix and eventually the evaporator did need replacement.

http://neons.org/neontsb/TSB/24/241197.htm

http://www.wjjeeps.com/tsb/tsb_wj_2400606.pdf

 

[Durang-goer]

Very good article Crown !