My 1992 F150 supercab has had this mildew " dirty socks" type odor for some time. I've stripped my truck down but just can't get rid of the smell. I think I've narrowed it down to some kind of bacteria or fungi growing in my heating system. A mechanic friend told me probably between the moisture laden fins of the evaporator core. Has anyone every had this same problem and how did you get rid of the smell? I've heard of people using Lysol, but I'm unsure where and how to apply it. I've also heard about a product by a company called ATP that suposedly does a better job. It's called "Clean 'N Coat" and comes in a spray can. Has anyone ever used this product, know where I can get it and if they had success with it? Any help would be greatly appriciated. Thanks.

 

This smell can be reduced by having the dealer install a moisture purge module from TSB 99-19-5. The
module runs the blower fan for a while after vehicle is shutdown, in order to help evaporate condensation
that contributes to growth of stink producing mildew/mold nasties. The TSB also outlines a thorough
cleaning procedure.

 

Thanks for the info on the TSB. I'll see if I can get a copy. does anyone know if this something I can do myself or is it something that only the dealer can do?

 

Prior to the late eighties the A/C compressor was NEVER used if the OAT was below about 47 degrees F.(ref:84 Ford Thunderbird shop manual). Then some idiot decided that the majority of us were too discomforted by the hot airflow to the windshield to prevent and remove condensation on its interior surface.

So now we have systems that ATTEMPT to use the A/C to dehumify our cabin atmospheric environment all the way down almost to the point of freezing, usually about 35F!

Some manufacturers (Toyota, Lexus, etc,), those that rely on Denso USA (NipponDenso in Jp) to supply their climate control systems, rely exclusively on this method to prevent condensation on a cold windshield, even if the OAT is below freezing wherein the A/C can be of no help whatsoever.

When A/C was used only above 47F OAT the thin film of mositure remaining on the evaporator surfaces when you parked the vehicle for the evening would evaporate away into the ether fairly quickly.

But when you use the A/C at lower ambient temperatures the thin film of moisture left in the evening does not evaporate so readily and that longer term damp, dark and cool environemnt provides an excellent breeding ground for the literally thousands of types of mold, some of them toxic to the human race, that inhabit our earth.

So, minimize, to the MAX, your use of A/C in colder climates (nightly ambient average lower than 60 degrees F), turn it off manually if you system automatically engages it. If your system automatically uses the A/C to help defrost/defog/demist your windshield then avoid the use of this mode as much as is possible or disconnect the compressor clutch wire in colder weatehr if you can.

If you park your vehicle inside or under shelter then open the sunroof or windows slightly to let the moisture accumulated from that day's A/C operations evaporate into the great beyond.

 

Lysol sprayed into the heater box with fan "on" will help considerably

 

Thanks for the info. How and where do I gain access to the heater box?

 

Turn on recirc or max AC,blower on high,on pass side will hear air intake up under dash area.You will find the intake-squarish area with plastic grill to keep out kleenex.Spray Lysol into this area with fan running.Give it good squirt,let run then shut off & let set.We did this at Ford before TSB came out & it was still Nissans fix when I was there{Hey, I had to have a job}Hope this helps.If mildew smell is really bad may be carpet padding.Here many dealers pressure wash interiors[!],then vacuum out.Padding never dries but molders.We used to call it auction smell as the auction cars were cleaned this way.Nothing like a wet car with windows up in the hot summer sun.

 

This is good. Thanks. I'll give it a try since the weather is starting to warm up.