Hey guys, I have a friend that's having some car trouble. I have a feeling the shop they are using is trying to fuck them. It's possible my understanding of things isn't correct, but I'm hoping y'all can help sort me (and by extension, them) out.

They have a 2001 Ford Expedition 5.4L with AC/heater/blower problems. Their serpentine belt snapped so they had it towed to the shop. Evidently their whole AC compressor had come loose and was several inches away from where it needs to be. They ended up removing it and installing a delete pulley. The messed up AC compressor is in the trunk area.

According to the shop, they need a new AC compressor to have any temperature of air blowing into the cabin since that blower controls ALL airflow into the cabin. This reeks of bullshit to me, as in every other vehicle I've owned the heater core / blower were completely separate systems from the AC. In fact, I don't think my first car (1975 Nova) had AC at all, but the heater worked like a champ. I could see Ford combining them to save money (?!), but I've spent a while reading online and this doesn't appear to be the case. They look like completely separate systems that have nothing to do with each other. If my theory is correct: they should be able to get anywhere from luke warm to blistering hot air to blow out of the vents without the AC compressor attached.

Am I understanding things correctly, or am I missing something? Thanks for any info y'all can give!

Unless it's got fully automatic climate control, the shop is full of shit.

If it has fully automatic climate control (doubtful in '01), the shop is probably still full of shit. The compressor has absolutely no effect over airflow- it just makes the evaporator core chilly, cooling the air that passes through it.

I've NEVER seen a car that you can't remove the compressor from and not still have working heat and ventilation. And I've worked on some pretty obscure shit.

yeah, probably BS.

let's face it, most shops these days use the internet to diagnose issues when they don't know the models specifically. if i had a dollar for every time a mechanic said something that was utter BS because they thought i didn't know better, i'd be rich.

I'm going to call BS. The compressor doesn't pump air. You are correct in thinking that they should still be able to get luke warm or hot air coming through. The heating system works separately from the AC system.

I drove my black wagon (2003) for two years with a broken compressor and still had plenty of heat/hot air.

Something else is wrong with your friend's vehicle...blower motor, blower motor resistor, actuator, clogs...could be a number of things.

Posted by blitz if i had a dollar for every time a mechanic said something that was utter BS because they thought i didn't know better, i'd be rich.

This is precisely why I got my dad to start showing me how to fix my own car when I was 17. There's only been one shop that I've been to that actually took me out to show me what they needed to do to my exhaust and talked to me like an equal. Thankfully it's rare that my car actually goes in to a shop.

I talked to my father who is a Ford Explorer afficianado… he also worked at a Ford dealer. He has stripped several Explorers and owned at least 5 between him and my stepmother.

he says in no uncertain terms that the shop in question is full on full of shit. Like bucket loader full of shit.
that A/C compressor does just A/C... that's it.
he might have a working compressor over in his strip pile... but no idea the freight to Ontario from NY on that beastie.


one thing with GM's, which is not a Ford obviously... GM has their compressors wired so that when you turn the defroster on above 40F, it runs the compressor. Other than that, it just spins.