Air blowing at random speeds

[SCexpedition]

My wife has a 2016 Expedition EL Limited and the air conditioning and heat have been malfunctioning. I have put in a new blower motor and a new blower motor resistor and that has helped some of the problems but now it is blowing at random speeds. It will blow very low for several seconds and then it will start blowing very hard for several seconds, then drop back down to hardly blowing at all. Any suggestions on what is causing this or where to start looking?

 

[blackedoutlimited]

My wife has a 2016 Expedition EL Limited and the air conditioning and heat have been malfunctioning. I have put in a new blower motor and a new blower motor resistor and that has helped some of the problems but now it is blowing at random speeds. It will blow very low for several seconds and then it will start blowing very hard for several seconds, then drop back down to hardly blowing at all. Any suggestions on what is causing this or where to start looking?

Is it on auto setting?

 

[Frank Wilson]

Similar thing happening the past couple days.
What's really strange is that when I turn off the system, the blower goes into high speed for awhile.

 

[SCexpedition]

Is it on auto setting?

It was stuck on auto and swapping out what I did made it so it can be taken out of auto and manually controlled.

 

[SCexpedition]

Similar thing happening the past couple days.
What's really strange is that when I turn off the system, the blower goes into high speed for awhile.

Exact same thing happened on hers. It stopped when I replaced the blower motor and blower motor resistor but now there is no rhyme or reason to the speed of the fan.

 

[99WhiteC5Coupe]

My wife has a 2016 Expedition EL Limited and the air conditioning and heat have been malfunctioning. I have put in a new blower motor and a new blower motor resistor and that has helped some of the problems but now it is blowing at random speeds. It will blow very low for several seconds and then it will start blowing very hard for several seconds, then drop back down to hardly blowing at all. Any suggestions on what is causing this or where to start looking?

Did you replace this part also: https://static.nhtsa.gov/odi/tsbs/2019/MC-10163573-0001.pdf

Over the past few years, there have been numerous posts on this forum involving problems with this original part, and it has been corrected by replacing this part also.,

 

[Motorcity muscle]

Need to get actual voltage readings at motor, replacing parts without troubleshooting rarely fixes the problem. Was wiring making good connection and not melted at the resistor harness?

 

[sthomp99]

There are several of these threads. I am experience similar trouble with 2016 XL. Blower powered with ignition ON (HVAC: Off), Relays Good, Blower "Resistor" Good. Work around for now is ground blower ground (Now Blower: High with Ignition ON). Problem likely CCM25 the HVAC Control Module. No luck sourcing $200+, salvage yard next... Wiring diagram found here on another tread...

 

[sthomp99]

My replaced Blower Resistor was BAD. The DORMAN 973-399 is a great solution with beefy 10ga wire connector included. The GOOD Blower Resistor for "Electronic Manual Climate Control" fixed the issue straight away.

 

[99WhiteC5Coupe]

My replaced Blower Resistor was BAD. The DORMAN 973-399 is a great solution with beefy 10ga wire connector included. The GOOD Blower Resistor for "Electronic Manual Climate Control" fixed the issue straight away.

Did you receive your letter regarding the HVAC front blower motor?

https://static.nhtsa.gov/odi/rcl/2022/RCMN-22V648-9794.pdf