AC low speed fan

[Jef1f76]

2015 Explorer. Compressor is 1.5 years old and does not kick on. Cooling fans are less than one year old. Low speed fan does not kick on. Shop wants to replace the entire AC system for $3,000 saying the compressor failed internally. Seems to me like something electrical - sensor, switch, computer - has failed and not triggering the low speed fan on which isn’t allowing the compressor to run. Compressor was running fine in the fall. Thoughts?

 

[peterk9]

Welcome to the Forum.
Was the replaced compressor a genuine Ford part? If so, it has a 2 year warranty on parts and labour. Does the compressor kick in om Max A/C?

Peter

 

[Jef1f76]

Welcome to the Forum.
Was the replaced compressor a genuine Ford part? If so, it has a 2 year warranty on parts and labour.

Peter

Ford dealership replaced it but with an autozone part, one year warranty

 

[peterk9]

Does the compressor kick in on Max A/C?

Peter

 

[Jef1f76]

Does the compressor kick in on Max A/C?

Peter

Does the compressor kick in on Max A/C?

Peter

It doesn’t. The shop that wants to replace the system says the compressor starts to run and tries to trigger the low speed fan but the fan doesn’t start and it fails out. To me that means the compressor is trying to run and hasn’t “internally failed”

 

[peterk9]

Have you checked associated fuses?

 

[Jef1f76]

Have you checked associated fuses?

I have and they all look good. Relay seems fine (clicks) but haven’t replaced it

 

[Jef1f76]

I have and they all look good. Relay seems fine (clicks) but haven’t replaced it

The shop “didn’t get into the fans” to see what was going on which is why I’m questioning replacing the entire system versus looking at why the low speed isn’t kicking in

 

[ProjectSHO89]

I'd suggest finding a shop that actually understands HOW the system is supposed to operate so they can accurately diagnose it. A Ford dealer is far more likely to have a technically competent and experienced technician over an independent shop that works on anything that comes in. Check qualifications....

This thing is a computer on wheels and, if the person trying to diagnose it doesn't understand that, they'll waste considerable time and money. The alternative is for you to learn how to do the job which may or may not be in your wheelhouse. If it is, we can certainly help.

There are a number of fault conditions that will inhibit A/C compressor operation by design. If the inter-dependencies are not understood and investigated, things will go sideways very quickly.

 

[RangerNutt]

What @ProjectSHO89 said. Any refrigerant cycling system will kick out when either condenser or evaporator fan fails to run.

Most importantly (to your wallet), the cabin blower not moving air may be all that's wrong.

A crude test might be to force air through the cabin intake (such as by using a shop vac on blow), then turn a/c on. If compressor cycles normally and air gets cold, the cabin blower (or component in its driver circuit) is almost certainly the culprit.

 

[ProjectSHO89]

The cabin blower, if inoperative, will NOT cause the reported symptoms. At least, not immediately. The refrigeration system would operate normally until the evaporator temperature sensor detected the temp dropping too low indicating imminent evaporator icing. That would typically take several minutes, at least.