A/C issues. Need help.

[Balazar]

Ok at the beginning of summer I had the A/C on. Left my truck parked and running to grab something from the house real quick. I came back and my neighbor told me that something blasted out from under the truck. White reside in the sand on the ground under the passenger side of the engine compartment. I think it released r134. Not sure. Then the A/C clutch started cycling about every 5 seconds. 5 seconds on 5 seconds off. Does this when I'm parked. Not sure if it does it while moving. I went to get some r134 and fill it back up. I hook up the bottle to the low pressure port and the gauge is in the red. Compressor kicks on and it goes to green then compressor kicks off and shoots back to red. It kind of sounds like it releases a tiny bit of r134 every time it kicks off. A/C blows hot when standing still idling. Blows cold at highway speed. Any ideas on how to fix this? Fan clutch? Pressure transducer? Blockage?

 

[bigceltic]

Look at Tuesdak's reply to my question in this thread https://www.turbodieselregister.com/threads/fan-duty-cycle-question.269401/#post-2641870 (#7)

 

[AH64ID]

Use your smarty to check for soft codes. Often the fan won’t set a CEL.

 

[Tuesdak]

You wasted your money on the "quick fix" can. The system needs to be evacuated (recover refrigerant and then pull a vacuum) and recharged by weight. No, the WAG gauge can isn't the proper way to do it. That can was 1/2 the cost of the shop labor to do just this. The AC clutch cutting off while filling the can can overpressure and burst that flimsy can! Safety Goggles may save your eyes and eyesight from the flash freeze if the can bursts.

If one insists on charging with a can get a big electric fan blowing on the condenser and jump the compressor clutch to be running 100% of the time.

I suspect your fan clutch is aged out if it's over 5 years old. $Ouch$ but replace it with a MOPAR part. No, not the aftermarket likely doesn't work well part: get a MOPAR part. Did the condenser get clogged up with a bunch of bugs?

Condenser gets too hot from not enough fan speed cooling it off, pressure rises, and the system either blows up or vents out the safety relief valve. It's more impressive of a cloud when the high side line seal lets go at the compressor.

Even new these 03-07 trucks have a defect where the ECM doesn't kick out the compressor when it reaches system explosion pressures of 450+ psig. It just vents half the charge out the safety relief valve.

https://www.turbodieselregister.com...rams-ecm-defect-opening-the-ac-relief.258779/

 

[Balazar]

I never screw the coolant bottle into the cheap plastic ac filler device until I get a read on the pressure. My fan clutch is newer. I replaced it last fall. I use a winter front in winter and bug screen in the summer. The condenser may have some dust and road grit in it. I will give it a good cleaning. I used the smarty and alphaOBD to scan for cell codes. Nothing came up. I did graph the fan speed with alphaOBD and it seems to be normal. I'm sure the system would benefit from a purge and correct filling. But is it really necessary to make it work? I can graph the high side pressure with alphaOBD but I'm not experienced with ac systems and I don't know what is normal.

 

[Tuesdak]

I'm sure the system would benefit from a purge and correct filling. But is it really necessary to make it work?

Did you just start the truck cold when this happened? If so I described that failure in the linked thread and 1/2 or more of the system charge is gone.

Think of it this way: Will your Cummins Diesel run with 1 gal of oil in in instead of 3 gal and do you want to find out for how long? If you dump 4 gal or more of oil in... Turbo drain gets covered turbo oil seals blow and engine runs away. AC systems like ours do not have a dipstick to measure refrigerant level. The "oil level" in the system is another headache: some compressors have a way to determine the system oil level.

So refrigerant is a specific pressure at a specific temperature. Don't matter if the system is near empty or near full the gauges will read the same for the temperature of the system parts. So gauges indicate the system is not out of liquid and some other rarer trouble. Gauges can tell you it's low and then you evac and recharge the system. If they are still low you replace a faulty compressor. If the passenger side is warmer than the driver side this means the evaporator isn't full of refrigerant.

Even then you don't know how much is in the system. It needs to operated with a flooded evaporator to work properly and more important move the oil in the system back to the compressor. Flooded evaporator? Yes the system capacity is determined by filling up the evaporator with liquid refrigerant and adding 1/4 LB to the accumulator as a leakage reserve. Generally the charge needs to be within 1/4 LB. You are not going to be able to do that with gauges. This is why these type of orface tube AC systems require an evac and recharge to work their best.

Is your fan clutch a MOPAR unit? Your system likely blew the charge out the relief valve on the back of the compressor from the condenser being too hot. I am guessing most likely. Now it's up to you to go over the system and confirm this is where the refrigerant blew out at. It's possible the high side compressor to hose seal blew out and resealed. It's also possible the compressor is failing and clogged the orface tube.

If you find no leaks but the engine oil filter is covered with dye or an oily residue the system vented by the relief valve.

 

[Balazar]

Did you just start the truck cold when this happened? If so I described that failure in the linked thread and 1/2 or more of the system charge is gone.

Think of it this way: Will your Cummins Diesel run with 1 gal of oil in in instead of 3 gal and do you want to find out for how long? If you dump 4 gal or more of oil in... Turbo drain gets covered turbo oil seals blow and engine runs away. AC systems like ours do not have a dipstick to measure refrigerant level. The "oil level" in the system is another headache: some compressors have a way to determine the system oil level.

So refrigerant is a specific pressure at a specific temperature. Don't matter if the system is near empty or near full the gauges will read the same for the temperature of the system parts. So gauges indicate the system is not out of liquid and some other rarer trouble. Gauges can tell you it's low and then you evac and recharge the system. If they are still low you replace a faulty compressor. If the passenger side is warmer than the driver side this means the evaporator isn't full of refrigerant.

Even then you don't know how much is in the system. It needs to operated with a flooded evaporator to work properly and more important move the oil in the system back to the compressor. Flooded evaporator? Yes the system capacity is determined by filling up the evaporator with liquid refrigerant and adding 1/4 LB to the accumulator as a leakage reserve. Generally the charge needs to be within 1/4 LB. You are not going to be able to do that with gauges. This is why these type of orface tube AC systems require an evac and recharge to work their best.

Is your fan clutch a MOPAR unit? Your system likely blew the charge out the relief valve on the back of the compressor from the condenser being too hot. I am guessing most likely. Now it's up to you to go over the system and confirm this is where the refrigerant blew out at. It's possible the high side compressor to hose seal blew out and resealed. It's also possible the compressor is failing and clogged the orface tube.

If you find no leaks but the engine oil filter is covered with dye or an oily residue the system vented by the relief valve.

Wow, thanks for that. I guess I have a lot to learn about A/C. I don't have the tools to do a purge so I guess the next thing I need to do is take it to a shop that can purge and refill it. Should I be concerned that there may be a bad seal somewhere? What is the best way to clean the condenser? My fan clutch is aftermarket. It seems to be fine though. I put a tachometer on it and it's reading within a few % of what the AlphaOBD graph says. I still have the Mopar one. Long excruciatingly expensive roadside repair story short; it needs a some wires and a new connector to be used again.

 

[Tuesdak]

Any AC shop will check for leaks. The good ones consider the cooling fan as it's often overlooked because it works well enough for just the engine.

I would recommend that you get a new MOPAR clutch on your truck. The old worn one with missing wires isn't worth the risk or the trouble. It's known that aftermarket clutches are just not good enough.

I have had bugs and other things like cotton fuzz from local cotton fields plug the condenser before: Sounds like yours is in good shape. I use a garden hose and a nylon brush or compressed air carefully depending on what is plugging it.

You want to see around 600 RPM with the fan kicked out. Less like 350 RPM is just too slow to kick in fast enough with the AC demand.

Use high idle on the truck when leaving it and do not use the high blower setting. This gives the engine fan more RPM to work and the lower inside HVAC fan speed reduces AC heat load to allow more time for the engine fan to kick on.

If you want to help even more strap a electric cooling fan on the condenser that comes on with the compressor.

 

[BigPapa]

Not a Dodge and not a diesel, but one of the guys at the shop had a Suburban with a 5.7L he’d bought and had to put a compressor, accumulator/dryer, condenser, and orifice tube on it. It didn’t cool like it should so he had me order another compressor because he felt that one was bad. I asked about his fan clutch, “no, it’s good.” The second one didn’t do any better so he wanted a different brand. I again suggested he replace the fan clutch. He finally replaced the fan clutch after his buddy recommended it and all is good.

 

[Balazar]

Ok, I ran some diagnostics on my fan. It runs just under 300 rpm most of the time. When it gets a request from the computer to increase in speed it then runs 650-750 depending on the engine rpm. Is this acceptable? I also noticed the ac compressor clutch is rattling and making a hell of a racket when watching the clutch kick on and off. With the truck off the triangular plate on the front of the ac compressor moves around freely on the three studs and has about a 1mm gap to the pulley. The dampeners that go on the studs are all gone. Is just the clutch bad or is the whole compressor junk now? This has been the most mysterious problem that I have ever had on this truck.

 

[Tuesdak]

Ok, I ran some diagnostics on my fan. It runs just under 300 rpm most of the time. When it gets a request from the computer to increase in speed it then runs 650-750 depending on the engine rpm. Is this acceptable? I also noticed the ac compressor clutch is rattling and making a hell of a racket when watching the clutch kick on and off. With the truck off the triangular plate on the front of the ac compressor moves around freely on the three studs and has about a 1mm gap to the pulley. The dampeners that go on the studs are all gone. Is just the clutch bad or is the whole compressor junk now? This has been the most mysterious problem that I have ever had on this truck.

Can you get your money back on the aftermarket fan clutch? IMO the RPM is way too low and the source of your AC problems. Replace it with a new MOPAR clutch.

It should be around 600 RPM kicked out and 1500 RPM to move enough air for the AC at idle. (The fan is not needed for AC above ~45 MPH.)

A picture would confirm, but, sounds like the compressor clutch burned up. Worst case: Don't drive it as the idler bearing on it's pulley is likely also ruined. High temps from clutch slippage can hurt the shaft seal on the compressor.

That may be the reason it could only kick in for 5 seconds - bad clutch. A compressor failing can also hurt it's clutch. How much overheating damage did the sub-par fan clutch do to the AC system...

With the high cost of a compressor clutch kit, PIA of installing it, gaping it correctly, and you already need an evac and charge: it's easier to just replace the compressor.

You would have to look into the system to see if it's full of debris or if you can just replace the compressor. Most places require replacement of the orface tube line, accumulator, maybe condenser, and system flush just to warranty a new compressor. Suggest you use a OEM Denso compressor. Plenty of junk knock-offs out there that can make you eat the labor and parts just listed if they die under warranty. You will not care about warranty on a hot day even if the shops eats it all when they can get it back in. Ask them to use the best parts or find a place that will. It's like $100 more for an OEM compressor most online places vs. low bidder knock-off.

An alternative failure is possible: Fan clutch overheated AC system and compressor clutch burned up. Maybe you can just replace the compressor clutch, fan clutch, belt because it would have seen the heat from the AC clutch burning up, and the system will be fine. Is the engine oil filter coated with AC oil and dye? Aka did the system vent or just fry the compressor clutch?

I have cut the V-belt off a few times on AC compressors after the impressive smoke show of a clutch failure.

 

[Balazar]

Can you get your money back on the aftermarket fan clutch? IMO the RPM is way too low and the source of your AC problems. Replace it with a new MOPAR clutch.

It should be around 600 RPM kicked out and 1500 RPM to move enough air for the AC at idle. (The fan is not needed for AC above ~45 MPH.)

A picture would confirm, but, sounds like the compressor clutch burned up. Worst case: Don't drive it as the idler bearing on it's pulley is likely also ruined. High temps from clutch slippage can hurt the shaft seal on the compressor.

That may be the reason it could only kick in for 5 seconds - bad clutch. A compressor failing can also hurt it's clutch. How much overheating damage did the sub-par fan clutch do to the AC system...

With the high cost of a compressor clutch kit, PIA of installing it, gaping it correctly, and you already need an evac and charge: it's easier to just replace the compressor.

You would have to look into the system to see if it's full of debris or if you can just replace the compressor. Most places require replacement of the orface tube line, accumulator, maybe condenser, and system flush just to warranty a new compressor. Suggest you use a OEM Denso compressor. Plenty of junk knock-offs out there that can make you eat the labor and parts just listed if they die under warranty. You will not care about warranty on a hot day even if the shops eats it all when they can get it back in. Ask them to use the best parts or find a place that will. It's like $100 more for an OEM compressor most online places vs. low bidder knock-off.

An alternative failure is possible: Fan clutch overheated AC system and compressor clutch burned up. Maybe you can just replace the compressor clutch, fan clutch, belt because it would have seen the heat from the AC clutch burning up, and the system will be fine. Is the engine oil filter coated with AC oil and dye? Aka did the system vent or just fry the compressor clutch?

I have cut the V-belt off a few times on AC compressors after the impressive smoke show of a clutch failure.

The truck is parked for now. I'm positive the AC clutch is buggered. I don't think the aftermarket fan clutch ever performed as it should have. Thinking about it now, I was constantly watching my temps when towing heavy after installing it. I just chalked it up to it being blazing hot last summer. It can't hold a dollar bill to the condenser when I engage it with alphaOBD. It is a duralast from autozone. I still have the receipt ($61). For now I will spend my cash on an OEM fan clutch. $415 is the best deal that I have found. If anyone knows of a better deal please post it. I will also replace the ac compressor clutch. I'm confident that the compressor is still working. No residue on the oil filter. If the compressor has pooped the bed, I will just no longer use my AC until I can replace all of the parts in the system with high quality ones.

 

[seafish]

Another member recently posted an excerpt from the FSM about the absolute necessity of increasing engine rpm to a certain speed directly after installing a new fan clutch.

the stated purpose of doing so is to properly distribute the oil in the clutch mechanism am for proper operation

while this sounds kinda ridiculous on the face of it he actually reinstalled an older oem fan clutch that he had already replaced thinking it was part of his AC problems

After reinstalling the old fan clutch and following the FSM protocols both the old clutch as well as the rest of his AC started working properly!!!

so all that said it is probably worth looking into that procedure

just my .02

 

[Balazar]

I found the blurb in the FSM for the post installation procedure: "NOTE: Viscous Fan Drive Fluid Pump Out Requirement: After installing a new viscous fan drive, bring the engine speed up to approximately 2000 rpm and hold for approximately two minutes. This will ensure proper fluid distribution within the drive."

It seems like most people cruise at 2k rpm's constantly. This procedure must just be in place to make sure the fan clutch works with the vehicle stationary in the shop before it is driven on the road. I can see how someone might install a new fan clutch and then start the vehicle and let it idle waiting for it to kick on for testing and it wouldn't perform properly because it had never been taken to higher RPM for long enough to even out the fluid inside.

 

[Balazar]

Ok, here I am two months later. I replaced the fan clutch and fan blade with OEM. The duralast fan clutch was weak and only spinning at half speed. It also chewed up some fan blades because it's bracket for keeping the wires clear of the blade was about an inch shorter than OEM.

I couldn't get the correct clutch parts for months. The first one was lost by USPS, the second one was a 6 groove pulley instead of 8. Third one had a damaged pulley from shipping. I took the bearing from the kit with the 6 groove and put it in my 8 groove pulley to get me along through the summer. No magnet or clutch was installed with it because the pulley was a little out of round and I didn't want it to rub and blow up.

I now have a new compressor pulley w/ bearing, magnet, and clutch. I installed all of this last night. My problem now is that the magnet doesn't engage the clutch. I put a multi meter on the connector for the magnet and it's getting 11.26 volts. Do I have a bad magnet? I plugged in the magnet from the damaged kit to see if it would work. Well it doesn't do anything either. What now? There is a 10a AC fuse under the hood and it is good. Is there a relay somewhere to check? Did I burn up the TIPM when the last clutch went out? I need help.

 

[Tuesdak]

I put a multi meter on the connector for the magnet and it's getting 11.26 volts.

Is this with the magnet plugged in? I use push pins to backprobe the connector. If the magnet isn't plugged in when taking a voltage reading any high resistance connection will not be found. (Reads good voltage unplugged with no current: plug it in and voltage drops like a rock to near 0 with a high resistance connection.)

An ohm test of the magnet will also answer questions. Keep in mind to measure it both ways as there may be a diode built in to the magnet.

 

[BigPapa]

What’s your plate gap?

 

[Balazar]

What’s your plate gap?

The instructions said to mount the clutch and spin the pulley. If the clutch contacts the pulley put the spacer washers in one at a time until the pulley spins freely without touching the clutch. That is what I did. There is one washer in there. I would say 15-20'''. I can put a feeler gauge in there and find out.

 

[Balazar]

Is this with the magnet plugged in? I use push pins to backprobe the connector. If the magnet isn't plugged in when taking a voltage reading any high resistance connection will not be found. (Reads good voltage unplugged with no current: plug it in and voltage drops like a rock to near 0 with a high resistance connection.)

An ohm test of the magnet will also answer questions. Keep in mind to measure it both ways as there may be a diode built in to the magnet.

The 11.26v that I got was at the connector with the magnet unplugged. I will check with it plugged in and get the resistance from the magnet in the AM. I have 2 spare magnets now. I think there may be a fried relay somewhere because the old magnet that came out had taken quite a beating. The coils were showing, indicating that it probably shorted the circuit.

 

[Tuesdak]

What’s your plate gap?

Come to think of it... if one taps the clutch plate toward the magnet and it snaps in when the power is on: that would be quick and dirty answer of "too large a gap".