After suffering musty A/C discharge to the point of having black mildew growing in the cab of my 2001 S’Crew Lariat, I decided it was time to clean the evaporator. I purchased a DWD2 kit (www.dwd2.com) – per a recommendation on this board – and used it to douche the evaporator this past Sunday.

Everything went fine with the installation and use of the kit. The kit worked as advertised and I was happy with the results – until Monday morning. While driving to work on Monday, I smelled something burning. I later noticed that my temperature blend controller was no longer working. Fortunately, since I live in Houston, it broke on a somewhat cool setting.

On Tuesday, I got to thinking that perhaps gunk from the evaporator coil crapped up the blend door mechanism, so while playing with the temperature controller, I pounded on the evaporator housing with my hand. The system went to full HOT.

Later on Tuesday, I drove the truck again and the system had returned to the somewhat cool setting it died on earlier.

I tend to think the problem lies in the blend door actuator, but after seeing photos of the blend door actuator (from a Mark VIII); I have a hard time believing that the actuator motor was affected by the foam cleaner. Also, why did it take a day to die?

I appreciate any advice from this board before I invest a lot of time and effort tearing my dash apart trying to locate the damage.

By the way, I have read the posts on the Explorer blend door failures and do not think that applies in this instance.

Thanks in advance,
Jeff

 

The LD F series blend door actuator is mounted on the bottom of the plenum, so if there was a large amount of goop in the case it could certainly have run down the blend door shaft and contaminated the circuit board in the controller.

 

Thanks for the response, Homerwinzlow,

I just removed the blend door actuator. After getting it off, I can see how liquid could run down the shaft and into the housing. Strangely, the housing is dry on the inside, but the actuator does appear to be dead. I will stop by the local dealership tomorrow and pick up a new one.

My next question is, when installing the new actuator, how do I match the position of the actuator with the position of the door? I can see how getting this wrong could damage the new actuator.

After following the Chilton’s manual, I still could not remove the floor ductwork, so I am working in tight spaces.

-Jeff

 

Homer,

Mission accomplished! Thanks for all your invaluable input.

-Jeff

P.S. It appears that the DWD2 evaporator cleaning kit was the cause of the actuator damage. On the 2001 F-150, the actuator driveshaft inserts into the bottom of the HVAC plenum to drive the blend door. This shaft was the leak path of the cleaner into the actuator.