Hi all. First post, but I've lurked on and off searching for service and maintenance related ideas. Hoping to get some feedback / insight on the following.

The ac/heat blower in my 2013 FX4 ecoboost (with a lot of miles on it - over 200,000 km/120,000 miles) has been acting up for the past 2 months or so. It quit running late June, but I could get it to work again by disconnecting the battery and/or replacing the blower fuse. I did this a couple of times to get it to operate, but as of a couple of days ago, the fuse / battery disconnect fix couldn't get the blower to go back on. So, after reading through some additional related posts, I pulled the blower motor resistor, noticed one of the female ports on the resistor was a little melted and discoloured, and replaced it (which, to the dismay of my wallet, was a $150 part compared to the $50 - $60 guys talked about on their posts). Happily, the blower kicked in immediately, ran for maybe 10 seconds, then stopped, then kicked back on, then off again. For the most part, it cycles on for 2 - 3 seconds, then off for 9 - 12, then back on for 2-3, then off again for 9-12, etc. At highway speed it stays like this, but at idle or low speed, every once in a while, it will cycle on for 4 - 5 seconds, then off again for 8 - 12, or on for 8 - 10 seconds, then off again for 8 - 12.

Anyone else have this issue? Or any thoughts as to what to check / replace next?

 

I would probably be considering doing the blower motor at this point. Or looking at wiring diagrams and doing some voltage test to see if there is a short causing this.

 

Thats how mine has always run, since day one. Comes on and runs maybe 10-20 seconds, then back off for maybe the same. Never thought about it as an issue. Engine stays cool and nothing is hurt. Little loud at a drive through at times, but no real issues. This is, of course, when it it hot, not all the time.

 

Blower motor cycles on and off or do you hear the compressor cycling on and off?

 

Yes, the compressor seems to function normally. And both the heat and the a/c work - at highway speeds both heat and a/c can be felt coming when the climate control is set to come out of the dash and/or floor vents. its just the interior fan that cuts in and out.

Today, the fan ran for quite a bit longer before it would cycle off.

 

Sorry for the confusion on this. Re-reading the replies, I should clarify that its the interior fan thats giving me grief - it cuts in and out - ie cycles on then off. The engine fan, etc, all seem to run normal - engine temp never gets warmer than just past the mid-point on the temp gauge.

 

Ahhh. That doesn't seem right then. I don't have any input on that one.

 

I am having the same issue at the top two speeds, i just replaced the blower motor resistor because the fan had stopped blowing at all speeds, not it blows at all but the top 2

 

My blower motor was just replaced due to this issue. On high it was pulling 30 amps, thus tripping the relay.

 

We just saw this problem in a 2014 F150 5.0L. The blower was only working intermittently, we replaced the blower motor and resistor from a local supplier. After the replacement the blower would cycle on/off when in the high position. After researching and finding nothing we decided to replace the resistor again - but with
a resistor from Ford. This fixed the problem. We had run into a problem with a sensor years ago that replacing with genuine Ford part fixed.