2013 EB, 61,500 miles and starting to get a musty smell from the vent's. The truck is pretty much babied and i can't think the last time it was in the rain. I don't wash it that often lately since i don't drive it much. Just within the last 2 weeks i get a musty smell with the ac on and it doesn't go away. Any Idears what i can check to get rid of this smell?

 

A common root cause of this is when people far too often shut their vehicle off with the ac running. It can induce mold growth since moisture is left behind and was not blown out. I was literally just telling a co-worker about this a few hours ago. The prevention is to turn the AC off before you reach your destination and run the blower full blast to clean out the system of moisture. I had the issue way back when I first bought my truck in '09. I used Lysol on the AC intake and ran it full blast and never had the problem again since I follow the procedure I described above. Works like a charm.

 

https://www.f150online.com/forums/hv...box-smell.html

 

Good advice, I will try that. Being in West Texas the AC is usually turned on around April and never touched until October, runs all the time.

Thanks for the link, I feel like a newb now by not using the search function

 

Quit eating so many tacos and farting in yer truck!

 

You don't have to turn off AC, all though it does help.

All you need to do is turn off "recirc" to allow fresh air in and out of the HVAC box

 

First thing that comes to my mind is the condensate drain is blocked which will leave stale condensate in the pan below the evaporator.

You know how you see condensate dripping from beneath vehicles when standing still while/after the A/C has been running - this is the condensate drain.

I had a similar problem when an old Bronco II with the area below the windshield (where the wipers are mounted) filling up with water. A quick stop at the body shop and he showed me where the drain tube was - snaked it out - it was full of debris.

The condensate drain will likely be much more difficult to locate and open up as the evaporator is buried in the dash. But maybe you could find the bottom end of the drain under the truck and try snaking it out with a piece of wire from the bottom.

Next time on a hot/humid day look under your truck while it is running with the A/C on for a while and see if it is dripping. If not that drain is probably blocked somewhere.

 

^^^ There was a TSB for some trucks about this. The drain is just a hole in the firewall with foam and a grommet sticking through. There is a bunch of foil backed insulation on the firewall. The grommet doesn't stick through the foam + insulation very much at all. If the insulation moves the water will then run back through the foam and into the cab. When mine did this I parked with the nose pointing downhill and got out the shop vac. I pulled over a gallon of water from under the carpet. I left the carpet rolled back for a few days and using the TSB as a guide pushed the insulation back and sealed the area with RTV. That resolved the issue for me. Other guys have bought a 45 or 90 plumbing fitting and made their own drain elbow.

 

Yea, it's diff. a moisture issue. just a bit laying there is all it needs. Doesn't take much to get mildew. If you have a draining issue get that taken care of. For the smell you need a disinfectant. As suggested, something like Lysol spray disinfectant can work. Turn on your AC and spray into the air intake at the windshield base. Just a few short bursts over 5-10 min., don't want it to pool either. Let the AC run to spread thru the evap., duct work, etc.. When you shut the truck off after you've been out and using the AC, leave the fresh air function on to allow airflow.

 

Same thing happened to me. It turned out to be molds from the a/c's evaporator coil.

 

The truck drips alot of condensation when it's humid outside with ac on. I started the truck yesterday and today and turned ac off and let the air blow full blast for about 20 mins. Actually seemed to help. Plan to drive it tomorrow and will definitely be using the ac throughout the day.