Hello. I have a Ford Econoline E350 XLT van. It recently has started having issues with the blower fan for the air conditioning. When traveling up hill or accelerating, the blower fan idles very low to the point it’s as if it has shut off. When leveling off or desired speed limit is reached the fans return to normal blowing. What could be the problem?

thank you.

 

We don't know at this time if it is a possible electrical or physical problem.

Might be a good idea to remove the blower motor and see if there is anything interfering with the motor running.

 

It is common for these vans to experience a problem with the vacuum reservoir which powers the climate controls. During periods of low vacuum, such as going uphill or accelerating, the controls switch to defrost mode. That may be what is happening to you. Check to see if the defrost is coming on, and let us know. There is a cheap fix for that.

 

Hey I have this same problem with my 2013 E350. On long hills it will go into defrost mode and quit blowing out of the vents. What’s the fix?

 

so there is a check valve to a vacuum reservoir in the dash that often goes bad, so that there is not enough vacuum to run the climate controls. To get at the check valve is exceedingly difficult, so the fix is to cut the vacuum line supplying vacuum to that reservoir, and re-route it through the doghouse into the cabin, where you can install another reservoir and check valve near the glove compartment and rejoin it to the climate control system. There are several videos on YouTube showing this, just search for Ford e350 vacuum defrost and check them out. I did it on mine about 2 years ago for about $40, and has been working fine ever since

 

I agree with Brad, the symptoms do point to a check valve problem resulting in the loss of needed vacuum to the the vacuum controls.

 

I don't know if the OP is describing his issue correctly. He didn't say if the blend doors are mode shifting back and forth with defrost. He said his "blower fan" seems to change speeds, which is strange and not dependent on vacuum.

 

As we all know , different folks will describe a problem different ways and we can only go by what we believe they are trying to tell us, so probably would be a good idea to ask for better details or description of just what is actually happening.

 

A correct diagnosis depends on a good description. Assuming then answering something that is unclear just costs the OP money if they try these suggestions with no results.

 

Unfortunately, by the time they get here a good number have spent considerable $$$ already and are asking for advice so they don't waste any more $$$.