Sorry for the lengthy post but I want to add as much detail as possible.

I have a 2004.5 ram 3500.SRW,no mods, gauges, Smarty Jr L1(tuner was stolen and I am stuck on this setting) 220k on motor and original 48RE. Original owner.

I live in a mild part of Montana and don’t use air conditioning much. When I do, it’s generally at freeway speed. Last August I went elk hunting in eastern Oregon, and temperatures were around 100 every day I noticed my air conditioning hardly worked at all at slow speeds while driving on back roads. A few days into the hunt. My water pump began to make noise and I tried to get to town. Water pump let go and I had to get towed to a shop. The shop replaced the water pump and he told me the engine was throwing a code indicating the fan clutch was bad, he couldn’t source one locally and recommended I replace it when I get home. I replaced the fan clutch in December and assumed everything was fine. I just made a road trip towing a 20 foot enclosed trailer and discovered the following symptoms, air conditioning very poor output at slow speeds, AC is just fine at freeway speeds, transmission temperatures rise rapidly at slow and moderate speeds, engine and transmission temperatures rise when climbing hills, all my research tells me this is a bad fan clutch on the off chance that clutch I replaced was bad, I swapped it out again. No changes in the symptoms. The other symptom is a high idle at 1000RPM. Three times engine coolant reading got into red after a hill climb and trans was reading over 240 (port is in the return line)

pulled codes, and there are no current trouble codes. There is a stored freeze frame with code P0483 with a bunch of data points.

Is it possible I got two bad replacements? One was a Hayden from Rock Auto and second was Napa house name. My intuition is telling me that either the ECM is not telling the fan clutch to engage or possibly something is bad with the wiring and it is not engaging at the higher level. Any ideas what I can check next? I am making my return trip to Montana on Friday and hope to get this sorted out before then.

Thanks for any and all help and suggestions.

 

Closely check the wires going to the fan. There are threads where these wires have been cut.

When you eventually fix the problem, let us know the problem.

 

I have air conditioning that doesn't cut it at any speed...
I have had code P0483 (Cycled the key three times) for many years and have never noticed any operational issue.
I know my fan is working as I hear it engage and disengage as I'm driving. This weekend I had the 10' Adventurer camper loaded and was flat towing a two door Suzuki Vitara up a long steep grade in 30*c heat (86F). Yes, the temperature rose, but never got excessive. Just a little above the half way mark.
It is just this year that my AC has stopped working.
I also have issues with the HVAC not blowing out the selected vent. I was thinking perhaps one of my (multiple) doors isn't switching the air to flow over the AC?

 

Round 2 of diagnosis:

followed troubleshooting steps from an online source and checked voltage at the harness with engine on and AC on.

pin 1 0v
pin 2 0v
pin 3 4.9v
pin 4 0v
pin 5 5.01v

all are correct except pin 5 which should read 12-14v

i checked voltage at the fuse #17 for the fan clutch and got 12v

So somehow the power is getting stepped down from 12 to 5 along the line? No obvious frays or breaks at the harness plug.

any ideas on next steps?

 

When it comes out of the fuse box where does it go? Sounds like a relay. If you didn't have low voltage at pin 5 I would have thought water pump was going out. Good luck!

 

it quickly joins the harness and disappears in the bundle. According to the diagrams online, it goes in and out of two other plugs before ending at the fan. No way I can pull all that apart and diagnose before Thursday.

 

Hope I’m not screwing something up…..I went ahead and ran a direct wire from the fan clutch fuse down to the fan clutch itself and tapped in to wire #5. Fired it up and fan is working! However it runs 100% of the time and not based on heat or AC usage….based on my research wire 5 should be 12v but wonder if actually 2 should be?

I am just trying to safely get back to Montana and then I can find the short or whatever issue is going on in that wire. Anyone think this is a bad idea? Any issue from a 1100 mile trip towing 8k with fan running non stop?

 

Hey, you have to do whatever gets you home. Personally I don't see any problem with the fan running the entire time it takes to get home. Yuh dun gud by hot wiring it.

 

Buddy of mine has an 8.3L Cummins in an FL80 with an air actuated fan. He needs to flip a switch to turn the fan on and off when he notices the temperatures getting warm...

You might be able to do the same. Run the fan wire into the cab and through a switch. Turn it on and off as required.

 

Was thinking about this problem and had an idea, so going to take a stab in the dark. Don't know exactly how the wiring in your truck is configured, but don't all fan clutches have a temperature sensitive switch? Am going to take a guess that yours could be located on the bottom of the rad. Find that switch, disconnect the 2 wires and short them together. See if that gets the fan going.

 

I “think” the signal comes from the ECM after it monitors temps and RPM and the moon phase and such. It decides when to activate it or not. Basically I did what you are suggesting. I eliminated the ECM and gave it power full time.

My long term goal will be to find the fault in the wire and fix that to restore functionality.

 

Well dang. Went on quick drive last night and fan no longer is running. Fuses look good and I don’t have multimeter access to diagnose. I’ll update thread when I can get back to it.

 

How did you manage to get it it fixed ?

 

Well good news bad news...turns out the short wiring that goes from the FC itself down to the wiring harness had wiggled loose (looks like I snapped the plug retainer when sliding in the fan shroud!) plugged it back in and everything works as it should as far as FC working and keeping everything cool. AC works great at slow speed, I can hear the fan kick in on hill climbs and when trans temps get high...

However a new (related?)issue has popped up! While pulling long grades, right before the fan kicks in, something begins making a very loud buzzing type sound. Not RPM dependent or variable but more of an on/off condition. Doesn't sound like a bearing either. Gauges looked normal and no codes are stored. It did not do this while the FC was not working.

I got some video of the noise and uploaded to YT as a short. I trimmed the video to eliminate about 90 seconds of beginning to pull the grade before it kicks in. Notice the fan noise starts immediately after sound begins. I tried to show gauges to get readings and they all appear normal. EGT reading is pre-turbo.

LOL YouTube has eliminated the sound from the audio! I will try something else...

No matter what I do, I cannot hear it on my PC...hear it just fine in the original video on my phone. Any ideas?

https://youtube.com/shorts/QIRYdLjq8i4?feature=share

 

I cannot hear this noise on my PC! I have to watch on my iphone to hear it just FYI.It is a loud buzzing noise and is very obvious. If you are thinking, "what noise?" then the audio is being filtered, try listening on something else...