AC problem, smoke out of vents

[greensplode]

i have a 98 mountaineer and it has a n ac problem, i was driving the other day and pretty heavy smoke started to come from the vents i shut off the ac and turned it back on later and it worked for a while and the same thing happened. the clutch is kickin on and off and the clutch is not stuck. i have no idea what is wrong. help me out please

 

[V8BoatBuilder]

Very strange - what did the smoke smell like? WHat was its color? Does the smoke happen with just the A/C or whenever the climate system is on?

I suspect your blower motor is shorting out and smoking. The smell would most likely be very acrid smelling and the smell should linger. I'm surprised a fuse didn't blow.

The other thing it could have been was a failure of the A/C evaportor. The "smoke" you saw was in fact the R134 refrigerant leaking out. Be very careful as this gas can cause blindness. How fast does the clutch cycle? If it is cycling very fast then this is most likely your culprit.

Look under the hood, passenger side by the firewall at the evaporator box/blower motor. Notice anything strange smoke patterns? I would not use the A/C untill you figure out exactly what the problem is.

 

[spta97]

...The "smoke" you saw was in fact the R134 refrigerant leaking out. Be very careful as this gas can cause blindness...

ACK!!!

In what capacity? I was planning on doing a recharge on my 2000 so I want to make sure I have all the info. Death I can deal with, blindness I cannot!

 

[V8BoatBuilder]

Wear saftey googles or a full face sheild. Don't use glasses. You'll be fine, its just a precaution.

 

[F14CRAZY]

Was it smoke or steam? If it was steam (which to me looked like smoke) then its possible the heater core took a crap. Happened in my '92. The smoke wouldnt stop in any position, hot or cold, unless you put it on MAX AC.

 

[Diggman33]

Is it possible it was condensation? I know old dodge's used to have that problem. Did the smoke/vapor smell or was it like a cool mist?

 

[mabulok]

System could need a recharge. Most likely condensate, very similar to "fog". Has to do with the temperature of the air coming out of the vents, and the moisture in the air. If it has an odor, then something's burning or leaking.

 

[greensplode]

it was not condensation, it had a wierd smell to it. and i forgot to mention that the fuse that controls the compressor clutch keeps blowing, and i half assed checked for burned wires by the blower motor but did not see any

 

[toddious]

you need to replace your blower motor controller. Most commonly you get a smell, and then the blower quits working completely because the EATC controller has failed. This would explain why your fuse keeps blowing as well.

This would be my guess. Part is about $50.

 

[Bwana Bob]

Smoke can also happen when the resistor used to control blower speed burns up. The resistor is in the blower air stream, hence the smoke. Does the blower now only work on high speed? The resistor is under an access cover in the engine compartment near the blower air duct.

If the compressor fuse blows, and the compressor is not seized, look for a shorted diode in the wiring harness to the compressor. I found a little diode buried in the harness that was shorted. I replaced it with a bigger (6 amp) diode.

Bob

 

[toddious]

haha, i think we're trying to help a dead cause.

after my reply yesterday, i noticed this thread is from 2004.....

oh well, in case anyone in the future has the same problem:

If you have EATC: probably your EATC blower motor controller
IF you have regular a/c: probably the blower motor resister.

Thanks for the extra input BOB

 

[gijoecam]

it was not condensation, it had a wierd smell to it. and i forgot to mention that the fuse that controls the compressor clutch keeps blowing, and i half assed checked for burned wires by the blower motor but did not see any

Define 'weird smell'... like something burning? Slightly metallic smell? Charred wiring insulation? Melting plastic? Sugary-sweet antifreeze smell? What?

The only wires routed directly through the HVAC system will be for the resistor pack (assuming you have manual HVAC knobs, not the electronic automatic temp controls). However, with the switch on high, the power bypasses the resistor pack all together...

If it's smoke, it'll accumulate in the cab, not dissipate. If it's water vapor, that's quite common... If it's hot and humid in the cab, and the cold de-humidified air coming out of the vents hits the warm damp air in the cab, it condenses the water vapor for a split second, but it dissipates within a few inches of the register. If it's smoke, it'll continue streaming into the cab and accumulate, getting thicker and stronger.

-Joe

 

[Cobraguy]

Guys...it's a 4 year old thread...

 

[toddious]

Guys...it's a 4 year old thread...

First of all I already mentioned this 2 posts ago

2nd of all, you can't really tell people to use the search function, if what they're going to find is unanswered questions. But thanks cobra.

 

[scottmi]

Was it smoke or steam? If it was steam (which to me looked like smoke) then its possible the heater core took a crap. Happened in my '92. The smoke wouldnt stop in any position, hot or cold, unless you put it on MAX AC.

regarding Max A/C.. that is the only setting that activates the Heater Control Valve (image), which uses vacuum to shut off circulation to the heater core (with or without A/C turned on 9lught showing). Turning A/C on or off does not activate the heater control valve. Max A/C is also the only recirculation mode, cutting off outside air (page 80, 1994 Explorer Owner Guide).