I noticed that my truck seems to always drip water from under the engine compartment. I realize this is normal when the AC is running, but pools of water drip out even when the AC has not been engaged. Then I also noticed that my legs seem to be bit cool, when I put my hand near the foot well I can feel cold air even when the vent air flow is off. Also, I've been noticing clicking noises when starting out (windows open) which sounds exactly like the AC compressor engaging and disengaging, even though the AC is not on (it's easy to tell when the AC is on as there is a light on the button, and the light does work when I engage the AC).

These clues lead me to suspect that my truck's A/C compressor is always engaged. Anyone else experience this?

BTW, my truck has the regular AC (not auto-climate control) and is factory installed (added that last part as mine is the work package, which unlike other F150 versions, do not automatically come with AC installed from the factory).


TIA MarkCh

 

what vent setting are you at? There are some settings (ie defrost, floor & defrost) where the condenser is active to dry out the air.

 

You should be able to shut it off and if you can’t something is wrong. Check it out in the driveway with your hood open so you can see the A/C compressor. Try all the various settings and see what’s what.

 

That's it, thanks . I didn't realize that when the air flow selector for the windshield was selected that the AC would engage. Since I like airflow but not the AC, I would choose the airflow for the windshield and the foot well with the temp dial to cold. I watch the AC compressor and listen, and noticed that the compressor would engage even though the AC button is not pushed and the AC light is not on.

Thanks,
MarkCh

 

I've noticed a thumping sound sometimes when my air conditioner is turned on. It's one hard thump when the AC is turned on. It's coming from the passenger side. Anyone else have this happen?

One more question here while on the subject of AC. Do you all turn off your AC before you shut off the truck?

 

That thump is your blend door slamming into position. Should not be audible.
If it’s loud, have it looked at under warranty.
In theory, you should always turn of the compressor, not necessarily the fan when you shut down. That way it wont be a drag when you start up in the morning. Nobody remembers to do that...
You should also switch off the compressor about one to two minutes before you shut down. That dries the condenser area, and stops mildew. Nobody remembers to do that either.
I wouldn't lose any sleep about it.
Chris

 

Just FYI, when you are running the defroster phase (blowing across the window) the air conditioning is on so that moisture will be extracted from the air by the evaporator, thus improving the defrost function.
It does help, but like you, I like to have air blowing up top, and wish you could shut off the compressor at that time. American car makers don't agree.
Chris

 

Thanks Chris I only hear it once in a while...just wondering if it was of any concern.

 

“Old School of thought” That’s a seventies' thing.

 

Doesnt your ignition kill all uneeded electrical systems at start up? I know the fan and other things shut off to get the most juice to the starter.

BTW....I am no expert, just curious.

 

It is probably not related to the A/C......

This is more than likely condensation from your exhaust. There is a small hole drilled in your muffler to allow water to drain from your muffler. In the event of short trips were EGT does not reach an acceptable level to burn of the accumulated water in the exhaust system. This keeps the muffler from rusting away so quickly

 

Actually the A/C compressor is never engaged at startup
Next time have someone fire it up with the A/C on while you are watching the A/C compressor clutch

And I think you meant to say the evaporator area not condenser.... Your condenser is the unit in front of the radiator, not the one behind the dash. And the condenser is going to be warmer than ambient temps if you are running the A/C

 

No that is a gas mileage and reliability thing. It's also not a big deal, just something that is recommended by many experts. Look it up. It's also strongly recommended in Japan, Europe, etc. where they care about gas usage. In Europe, they shut off their motor at stop lights. Saves a few bucks a month at their prices.

On the startup, talk about misunderstanding.
Even if the clutch may be disengaged during the CRANKING mode, I’m referring to after the engine lights.

It's after your truck first fires up, and attains minimum idle RPM, that the drag from the compressor is not beneficial, making the truck idle slightly worse while warming, and also increasing the chance of a stall. It also requires a higher idle speed (it's programmed in) thus increasing 'jolt' on the drive train when you engage the transmission. Many of us wait until our idle drops below 1000 RPMs. Other just slam them in gear. If you replace your truck every year or so, why would you care? If you keep it for a period of time, a little care increases it's life, reliability, and decreases your costs.

Drying the evaporator never mattered till the newer cars, say 93. And yes, tball, that was a major typo. Can't imagine a reason to dry the condenser...
It was late, and I had was tired. Sorry about that.
Chris

 

[Did you get an answer to the ac cluch problem?--joe




QUOTE=MarkCh]I noticed that my truck seems to always drip water from under the engine compartment. I realize this is normal when the AC is running, but pools of water drip out even when the AC has not been engaged. Then I also noticed that my legs seem to be bit cool, when I put my hand near the foot well I can feel cold air even when the vent air flow is off. Also, I've been noticing clicking noises when starting out (windows open) which sounds exactly like the AC compressor engaging and disengaging, even though the AC is not on (it's easy to tell when the AC is on as there is a light on the button, and the light does work when I engage the AC).

These clues lead me to suspect that my truck's A/C compressor is always engaged. Anyone else experience this?

BTW, my truck has the regular AC (not auto-climate control) and is factory installed (added that last part as mine is the work package, which unlike other F150 versions, do not automatically come with AC installed from the factory).


TIA MarkCh[/QUOTE]

 

well I have the thump too. It started every once in awhile but now it even does it at idle. It seems to do it in the mix heat and defrost or defrost position when the compressor kicks in. It started after a cam phaser replacement so I dont know if they messed something up but it is going to the dealer on monday. Ill let you know what I find out.