Fan clutch seems like it runs to much.

[C.Solomon]

New fan clutch few months back.

I noticed anytime the AC is on and I'm driving under 40 mph the fan clutch sounds like its 100% engaged.

It even does this with the defrost on (a/c button off)


When I first start the truck and driving is also sounds 100% locked up until operating temps are reached.


Just seems to me its ROARING all the damn time when its not needed.

Could a a/c pressure switch cause this?

Maybe its a faulty fan clutch?

 

[Ozymandias]

A/C is on by default if switch is turned to any defrost setting. It does not light the A/C indicator light then.

If the fan is running to much you can only examine with a computer as it will tell you the command and return values that the ECM demands.

Did you install an OEM clutch or Aftermarket?

 

[Tuesdak]

Just seems to me its ROARING all the damn time when its not needed

Does it stop ROARING at any time? Yes: It's fine. No: The bearings are locked up or other defect keeping the clutch locked up.

You have described to a "T" when the fan is needed for AC. Under 45 MPH and with the AC on. "Defrost" should be called "defog" because with a cold engine it can re-frost a windshield under certain conditions from overriding you and running the AC compressor. All OEM's I know of blindly run the AC in Defrost.

When I first start the truck and driving is also sounds 100% locked up until operating temps are reached.

This is called "Morning Sickness". The fan may have been "on" when the engine was shut off last time or the ports in the clutch may have lined up to allow the working fluid to move around locking it up. When you randomly don't have this and run the AC: the system likes to vent 1/2 it's charge out the safety relief valve due to an overlooked high pressure cut out in the ECM. No airflow over the AC condenser overheats the AC system even with a cold engine.

It's possible the AC system is overcharged causing high condenser temps/pressures triggering the ECM to be running the fan... and that's a WAG not knowing the history. (The Charge it yourself top-off cans are easy button to overcharge an AC system that needs to be charged by weight. No, you shouldn't "top off" these systems: recover and charge by weight only.)

 

[C.Solomon]

Did you install an OEM clutch or Aftermarket?

OEM

My wifes 12' Clutch fan does not operate like mine
My dads 06 and 17 do not operate like mine

Thats why its so noticeable to me.
Its 100% locked up soon as the AC is on, and never cycles off until AC is off or I go over 40 mph.
Besides being loud it takes so much power to turn that fan.

I have heard the fans engage in the other trucks list above, they are very brief and not nearly noticeable.
I put 300 miles on my dads 17 pulling a trailer over multiple days and heard the fan kick on 2-3 times for 5-10 mins at time
AC was on the entire time.

I guess my point is I don't think its operating as it should.

 

[AH64ID]

Being a computer controlled clutch and every year having slightly different programming I wouldn’t worry too much about it.

My 05 manual trans and 18 auto trans work very differently with the fan and ac.

I modified the fan programming on my 05 and got better AC performance and cooling while towing, even then it never sounded like dads 06 did, or my 18 does.

So if there aren’t any codes, you’re not overheating and the AC works I’d just chalk it up to programming.

 

[Ozymandias]

Like said, you can check this with a decent software. Then you'll see if it has to run and at how many rpms.

 

[STeichert]

My 07.5 does the same thing. The hotter the day the worse it is. If i get to 70 mph it all seems normal, but I agree its not normal at the lower speeds. It is very loud and annoying. My 05 and 18 don't do this at all. I had my a/c compressor go out last year and sent junk all through the system. I replaced the orifice tube, condenser and compressor, and after that is when all of this started. I think you are on the right track with a pressure switch, or it could be plugging in the system of some sort.

 

[Tuesdak]

@Ozymandias is correct. Screenshot of how I monitored my fan with a Smarty Touch here:
https://www.turbodieselregister.com...thermal-dispersant-on-an-ac-condenser.264486/

With the near AZ heatwave you have had up there being over 100 degrees and all, well, the fan is simply gonna run a lot. As your fan kicks out IMO it's working as designed. Further replacing an old slow to respond worn out clutch will make you think the new fan is running more simply because it is. Several including myself noted more fan running with a new clutch.

Without knowing what the ECM is seeing I have some guesses if you think it's too much: AC Pressure sensor, Clogged condenser, radiator, etc. with debris, or overcharged AC system. You can hit the condenser with an IR gun or a gauge set on the AC to see pressures. High side should be below 300 psig. (by the chart the condenser would be 160 degrees F @ 300 psig) You really don't want to be going over 400 psig or 180 degrees F. @AH64ID can say what pressures the AC brings the fan on at. An R134a pressure temp chart and IR temp gun can verify the need for the fan.

End of the day in my heat I would rather have too much fan than not enough. I grow tired of watching AC systems explode from overheating and paint EVERYTHING under the hood in that leak detect dye. The high pressure relief blowing off paints enough stuff as it is.

 

[AH64ID]

On a stock 06 G56 truck the fan is commanded to max above 350 psi. Max fan rpms for the AC is 1200, but that would be on top of any other fan demands, up to 2800 fan rpms. The initial AC fan speed demanded is 1000. Based on experience the fan sounds like it's on full around 1500 as the noise difference in 1500 and 2500 isn't nearly as much as 500 at 1500.

I say stock because I do not know if the Smarty has made any changes. I know the Smarty on my 05 didn't engage the fan for cooling as low as stock by a few degrees, but with UDC Pro I set it where I wanted it.

 

[Killer223]

Has to be programming. i had my truck tuned recently and now my fan is on almost all the time. even well above the 40 mph, ive had my fan on high or full lock for 80 miles doing 70 mph. when i flash back to "stock" it's back to normal.
i an get the fan to calm down if i tunr AC off till the fan slows down, then turn AC back on and i'll stay kinda calm, then eventually ramp back up.
i figure it's a temp or pressure issue. my High sides stays below 275. only once have i seen it at 306 i was idling with AC on high for about 45 min. soon as i was driving it went to the 275 mark.
so i'd agree it's a programming issue.
maybe i should have my tuner check into the tune for me???

 

[C.Solomon]

I know the Smarty on my 05 didn't engage the fan for cooling as low as stock by a few degrees, but with UDC Pro I set it where I wanted it

With UDC you can set fan parameters?

 

[AH64ID]

With UDC you can set fan parameters?

With UDC Pro you can, not with the standard UDC.

 

[CrewCabDiesel]

I'm in the same boat, but started after putting a new aftermarket fan clutch. Nothing is clogged, ac right where it's supposed to be, can pull 48 degrees from the vent on a hot Florida day. It's really getting to be PIA. Mine kicks on with a cold engine and rarely shuts off, sometimes ac is off still runs. I have been real light footed, completing engine break in, but I now I have 2000 miles on it, going to up the fuel to stage 3 "drive mode" and wind it up a bit, see if the fan kicks like it's supposed too.
Just noticed my signature is missing, early 2004 automatic, edge computer, built motor.
Kyle

 

[Ozymandias]

I'm in the same boat, but started after putting a new aftermarket fan clutch. Nothing is clogged, ac right where it's supposed to be, can pull 48 degrees from the vent on a hot Florida day. It's really getting to be PIA. Mine kicks on with a cold engine and rarely shuts off, sometimes ac is off still runs. I have been real light footed, completing engine break in, but I now I have 2000 miles on it, going to up the fuel to stage 3 "drive mode" and wind it up a bit, see if the fan kicks like it's supposed too.
Just noticed my signature is missing, early 2004 automatic, edge computer, built motor.
Kyle

Yes the aftermarket fan clutches are known to cause all kinds of weird behavior.
We say this for years on this forum to not buy them aftermarket.

 

[CrewCabDiesel]

interesting, Factory clutches last about 2 years under the miles and heat, just in time for the warranty to go out. I have replace 3 factory fan clutches and i am tired of $300 a shot! My last vender price before I bought this one is $561, so I'm trying something different. Also the fan clutch reguardless who makes it is controlled by the ECM. lets try focusing on the problem not critize someone for trying something else. How about some constructive ideas like Would clearing the ECM help? How can I set or reset the perimeters for the fan clutch? I have the Autoenginutiy software with full chrysler module (been using ove 10 years) is there anything it can test or program on the new version?
Thanks
Kyle

 

[Ozymandias]

With AE you can see the command and return values for the Fan. Thats all i found with mine (Giotto 2018) the last time i looked for the Fan.
So you know if it is working within specified parameters.
But like said, it is well known that this aftermarket clutches have more drag and therefor run faster all the time, but can still be within spec so don't set a CEL.

My first clutch lasted 16 years and 200K, now I'm on the second one.

 

[AH64ID]

The problem that generally occurs with aftermarket clutches is that they don't modulate well, so even a partial engage signal from the ECM turns them into fully engaged. So yes they are controlled by the ECM, but don't work how they ECM thinks they should.

 

[Yo Hoot]

And who makes Mopar fan clutches? How does Mopar justify their new outrageous pricing structure? Is there an aftermarket unit that IS the Mopar clutch?

 

[CrewCabDiesel]

Great question, love to hear the answer!