A/C Fan Speed: Shuts Off at 2 Highest Speeds
 

Hey folks, I have a small issue here with my A/C fan speed. The truck is a 2013 Ecoboost with 40k miles. I have 7 speed options on the A/C fan control knob, and whenever I go past the 5th one the fans shut down. If I go to the 6th or 7th fan speed setting, the system is still technically on (all the lights remain on) but the fan falls on its face and stops blowing entirely. Sometimes I can revive it by going back to a lower setting, other times it doesn't come back on and I have to shut the truck off and restart it. This issue occurs in both regular A/C and Max A/C Recirc modes. It's been nearly 100 degrees here lately, and I've noticed my engine fans have been running at high speeds, which is normal, but I'm wondering if perhaps having the A/C fan on high with the engine fan on high is too much for the truck. I'm not sure; I don't have a whole lot of knowledge in the A/C department.

Other than this issue, the A/C is working great. It blows cold and works on 5 out of the 7 fan speeds, which is great, because it's really hot here. So I can live with the issue because at least the A/C works, but I wanted to get some input because it seems like it shouldn't be doing this, especially with the truck being so new.

Any ideas? Thanks.

If you are still on warranty, go to the dealer.

Original battery I presume? Newer vehicles tend to act up with voltage isn't where it's supposed to be. Try testing the battery before you take it in?

A/C Fan Speed: Shuts Off at 2 Highest Speeds
 

I'm still under powertrain warranty, but at 40k I'm outside of the bumper to bumper.

Pat, yeah it's the original battery. I'll check it out. It's two years old now, and they usually only last 2-3 years in the heat down here. In my experience, the OEM batteries are not the best anyway.

Have you had the chance to check out the battery yet, JohnBoy88? Let me know if you decide to head in to your dealer; I'll do what I can to help out. :thumbsup:

Crystal

A/C Fan Speed: Shuts Off at 2 Highest Speeds
 

Yeah, I had the battery checked today. It tested good, sitting at 12.8 volts. Also, the A/C worked on all 7 fan speeds today.

Did they load test the battery or just voltage check?

A/C Fan Speed: Shuts Off at 2 Highest Speeds
 

Load Test. But it was one of those handheld things while the battery was still hooked to the truck. So it may not be all that accurate.

In the last few years I've had a lot of battery problems that just came and went. Sometimes the battery would die suddenly and completely with no warning and it would later suddenly start working again. I suspect that they have intermittent opens or shorts. I've owned and worked on all my own cars for decades but this is something new and now it's getting to be common. I had five batteries that did this in 2 years! The thing that they had in common was that most of them had come from Discount Auto Parts and ALL of them were made by Johnson Controls!

My point is even though your battery checked good, it could be intermittent. After being on this forum for a couple of years, I've realized that these trucks are very sensitive to low and/or erratic batteries and when they start exhibiting strange behavior that it's USUALLY the fault of the battery! I now recommend to anyone with a late model F-150 with strange electrical problems to REPLACE their battery before spending money for repairs or troubleshooting. Also it's not uncommon for even NEW batteries to exhibit this strange behavior so even if your battery is new, it's still worth putting in a different battery before investing elsewhere. I had one DAP battery that started acting up the same DAY that I bought it and I know of at least two others that had the same experience.

Assuming you went to a local parts store for your test

Batteries will hold a "surface charge" for 10 to 30 minutes after driving the vehicle. Best bet to help reduce surface charge is leave the headlights on while you go inside and wait in line for service. It will help drawn off the excess charge and get you back to normal resting voltage.

The handheld parts store testers do in fact do a load test - not just voltage but they measure cold cranking amps.

Right, but the battery can have a surface charge causing false positive test results

Forgot about this because I haven't been using the A/C much in the fall weather.

Quick update: I replaced the battery this past July, and the fan speed issue continued. I may have to just take it to the dealer even though I'm out of the warranty period. Fortunately I don't need the A/C as much this time of year (at least not the high fan speeds), and I've also been driving my other vehicle most of the time, so this isn't an urgent issue. However, any additional thoughts or ideas are appreciated.

I am from "Hot as Hades" Florida and I never needed to run the fan on high....just 3 or 4 at the most. The last 2 speeds are just WAY too loud for my taste.
Every other vehicle I have owned when the fan is functional and if it does lose speeds, it is always the lower speed resistors that fail.
I liked A/C units when they were simpler. :eek:

I have the same fan speed issue on my 2012 Lariat (shuts off using speeds 6 and 7). What was your final fix? Was it the blower motor controller?